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Sample records for water table occurs

  1. Effect of water table dynamics on land surface hydrologic memory

    Science.gov (United States)

    Lo, Min-Hui; Famiglietti, James S.

    2010-11-01

    The representation of groundwater dynamics in land surface models has received considerable attention in recent years. Most studies have found that soil moisture increases after adding a groundwater component because of the additional supply of water to the root zone. However, the effect of groundwater on land surface hydrologic memory (persistence) has not been explored thoroughly. In this study we investigate the effect of water table dynamics on National Center for Atmospheric Research Community Land Model hydrologic simulations in terms of land surface hydrologic memory. Unlike soil water or evapotranspiration, results show that land surface hydrologic memory does not always increase after adding a groundwater component. In regions where the water table level is intermediate, land surface hydrologic memory can even decrease, which occurs when soil moisture and capillary rise from groundwater are not in phase with each other. Further, we explore the hypothesis that in addition to atmospheric forcing, groundwater variations may also play an important role in affecting land surface hydrologic memory. Analyses show that feedbacks of groundwater on land surface hydrologic memory can be positive, negative, or neutral, depending on water table dynamics. In regions where the water table is shallow, the damping process of soil moisture variations by groundwater is not significant, and soil moisture variations are mostly controlled by random noise from atmospheric forcing. In contrast, in regions where the water table is very deep, capillary fluxes from groundwater are small, having limited potential to affect soil moisture variations. Therefore, a positive feedback of groundwater to land surface hydrologic memory is observed in a transition zone between deep and shallow water tables, where capillary fluxes act as a buffer by reducing high-frequency soil moisture variations resulting in longer land surface hydrologic memory.

  2. Cokriging model for estimation of water table elevation

    International Nuclear Information System (INIS)

    Hoeksema, R.J.; Clapp, R.B.; Thomas, A.L.; Hunley, A.E.; Farrow, N.D.; Dearstone, K.C.

    1989-01-01

    In geological settings where the water table is a subdued replica of the ground surface, cokriging can be used to estimate the water table elevation at unsampled locations on the basis of values of water table elevation and ground surface elevation measured at wells and at points along flowing streams. The ground surface elevation at the estimation point must also be determined. In the proposed method, separate models are generated for the spatial variability of the water table and ground surface elevation and for the dependence between these variables. After the models have been validated, cokriging or minimum variance unbiased estimation is used to obtain the estimated water table elevations and their estimation variances. For the Pits and Trenches area (formerly a liquid radioactive waste disposal facility) near Oak Ridge National Laboratory, water table estimation along a linear section, both with and without the inclusion of ground surface elevation as a statistical predictor, illustrate the advantages of the cokriging model

  3. Decreased summer water table depth affects peatland vegetation

    NARCIS (Netherlands)

    Breeuwer, A.J.G.; Robroek, B.J.M.; Limpens, J.; Heijmans, M.M.P.D.; Schouten, M.G.C.; Berendse, F.

    2009-01-01

    Climate change can be expected to increase the frequency of summer droughts and associated low water tables in ombrotrophic peatlands. We studied the effects of periodic water table drawdown in a mesocosm experiment. Mesocosms were collected in Southern Sweden, and subsequently brought to an

  4. Free product recovery at spill sites with fluctuating water tables

    International Nuclear Information System (INIS)

    Parker, J.C.; Katyal, A.K.; Zhu, J.L.; Kremesec, V.J.; Hockman, E.L.

    1992-01-01

    Spills and leaks of hydrocarbons from underground storage tanks, pipelines and other facilities pose a serious potential for groundwater contamination which can be very costly to remediate. The severity of the impacts and the cost of remediation can be reduced by various means. Lateral spreading of free phase hydrocarbons on the groundwater table can be prevented by pumping water to control the hydraulic gradient. Recovery of floating product may be performed by skimming hydrocarbons from wells, usually in combination with water pumping to increase the gradient. The environmental variables (water table gradient, water table fluctuations due to regional recovery wells, rates of water pumping)

  5. Changes in water table elevation at Yucca Mountain in response to seismic events

    International Nuclear Information System (INIS)

    Arnold, B.W.

    1996-01-01

    Investigation of mechanisms which could significantly alter the elevation of the water table at Yucca Mountain are motivated by the potential impacts such an occurrence would have on the performance of a high-level radioactive waste repository. In particular, we would like to evaluate the possibility of flooding a repository by water-table excursions. Changes in the water table could occur as relatively transient phenomena in response to seismic events by the seismic pumping mechanism. Quantitative evaluation of possible fluctuations of groundwater following earthquakes was undertaken in support of performance assessment calculations including seismicity

  6. Beaver Mediated Water Table Dynamics in Mountain Peatlands

    Science.gov (United States)

    Karran, D. J.; Westbrook, C.; Bedard-Haughn, A.

    2016-12-01

    Water table dynamics play an important role in the ecological and biogeochemical processes that regulate carbon and water storage in peatlands. Beaver are common in these habitats and the dams they build have been shown to raise water tables in other environments. However, the impact of beaver dams in peatlands, where water tables rest close to the surface, has yet to be determined. We monitored a network of 50 shallow wells in a Canadian Rocky Mountain peatland for 6 years. During this period, a beaver colony was maintaining a number of beaver ponds for four years until a flood event removed the colony from the area and breached some of the dams. Two more years of data were collected after the flood event to assess whether the dams enhanced groundwater storage. Beaver dams raised water tables just as they do in other environments. Furthermore, water tables within 100 meters of beaver dams were more stable than those further away and water table stability overall was greater before the flood event. Our results suggest the presence/absence of beaver in peatlands has implications for groundwater water storage and overall system function.

  7. Numerical tables. Physical and chemical analyses of Rhine water 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Tables present the methods of analysis and the data obtained on inorganic, organic, and radioactive impurities in Rhine water. The measuring stations were located in Switzerland, France, West Germany, and the Netherlands. (HP) [de

  8. Mechanism for migration of light nonaqueous phase liquids beneath the water table

    International Nuclear Information System (INIS)

    Krueger, J.P.; Portman, M.E.

    1991-01-01

    This paper reports on an interesting transport mechanism may account for the presence of light nonaqueous phase liquid (LNAPL) found beneath the water table in fine-grained aquifers. During the course of two separate site investigations related to suspected releases from underground petroleum storage tanks, LNAPL was found 7 to 10 feet below the regional water table. In both cases, the petroleum was present within a sand seam which was encompassed within a deposit of finer-grained sediments. The presence of LNAPL below the water table is uncommon; typically, LNAPL is found floating on the water table or on the capillary fringe. The occurrence of LNAPL below the water table could have resulted from fluctuating regional water levels which allowed the petroleum to enter the sand when the water table was a lower stage or, alternately, could have occurred as a result of the petroleum depressing the water table beneath the level of the sand. In fine-grained soils where the lateral migration rate is low, the infiltrating LNAPL may depress the water table to significant depth. The LNAPL may float on the phreatic surface with the bulk of its volume beneath the phreatic surface. Once present in the sand and surrounded by water-saturated fine-grained sediments, capillary forces prevent the free movement of the petroleum back across the boundary from the coarse-grained sediments to the fine-grained sediments. Tapping these deposits with a coarser grained filter packed monitoring well releases the LNAPL, which may accumulate to considerable thickness in the monitoring well

  9. Tables of the velocity of sound in sea water

    CERN Document Server

    Bark, L S; Meister, N A

    1964-01-01

    Tables of the Velocity of Sound in Sea Water contains tables of the velocity of sound in sea water computed on a ""Strela-3"" high-speed electronic computer and a T-5 tabulator at the Computational Center of the Academy of Sciences. Knowledge of the precise velocity of sound in sea water is of great importance when investigating sound propagations in the ocean and when solving practical problems involving the use of hydro-acoustic devices. This book demonstrates the computations made for the velocity of sound in sea water, which can be found in two ways: by direct measurement with the aid of s

  10. Empirical method for simulation of water tables by digital computers

    International Nuclear Information System (INIS)

    Carnahan, C.L.; Fenske, P.R.

    1975-09-01

    An empirical method is described for computing a matrix of water-table elevations from a matrix of topographic elevations and a set of observed water-elevation control points which may be distributed randomly over the area of interest. The method is applicable to regions, such as the Great Basin, where the water table can be assumed to conform to a subdued image of overlying topography. A first approximation to the water table is computed by smoothing a matrix of topographic elevations and adjusting each node of the smoothed matrix according to a linear regression between observed water elevations and smoothed topographic elevations. Each observed control point is assumed to exert a radially decreasing influence on the first approximation surface. The first approximation is then adjusted further to conform to observed water-table elevations near control points. Outside the domain of control, the first approximation is assumed to represent the most probable configuration of the water table. The method has been applied to the Nevada Test Site and the Hot Creek Valley areas in Nevada

  11. Relationships between water table and model simulated ET

    Science.gov (United States)

    Prem B. Parajuli; Gretchen F. Sassenrath; Ying Ouyang

    2013-01-01

    This research was conducted to develop relationships among evapotranspiration (ET), percolation (PERC), groundwater discharge to the stream (GWQ), and water table fluctuations through a modeling approach. The Soil and Water Assessment Tool (SWAT) hydrologic and crop models were applied in the Big Sunflower River watershed (BSRW; 7660 km2) within the Yazoo River Basin...

  12. Nitrogen Uptake in Soils under Different Water Table Depths ...

    African Journals Online (AJOL)

    A mathematical model was used to examine the interactions of NH4 + transport to rice roots, as well as to calculate root length densities required to relate N uptake to concentrations of NH4 + in solution around the rooting medium for three water treatments: water table 30 cm below the surface, 15 cm below the surface and ...

  13. Determination of naturally occurring radionuclides in El-Sin Water

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Al-Rayyes, A.H.

    2000-01-01

    Naturally occurring radionuclides levels have been determined in El-Sin water for the period of 1995 and 1996. water samples were collected from four sites, which are the main drinking water sources of the area. Radon concentration was found to vary between 0.88 Bq/1 in Lattakia main water supply site and 8.4 Bq/1 in El-Sin springs.The highest values found for other radionuclides were 51.6 mBq/1, 18.6 mB/1 and 24.8 mBq/1 for sup 2 sup 2 sup 6 Ra, sup 2 sup 1 sup 0 Po and total uranium (sup 2 sup 3 sup 4 U and sup 2 sup 3 sup 8 U) respectively. These levels are much lower than the maximum permissible levels in drinking water set by international organization.(author)

  14. Preliminary Water-Table Map and Water-Quality Data for Part of the Matanuska-Susitna Valley, Alaska, 2005

    Science.gov (United States)

    Moran, Edward H.; Solin, Gary L.

    2006-01-01

    The Matanuska-Susitna Valley is in the northeastern part of the Cook Inlet Basin, Alaska, an area experiencing rapid population growth and development proximal to many lakes. Here water commonly flows between lakes and ground water, indicating interrelation between water quantity and quality. Thus concerns exist that poorer quality ground water may degrade local lake ecosystems. This concern has led to water-quality sampling in cooperation with the Alaska Department of Environmental Conservation and the Matanuska-Susitna Borough. A map showing the estimated altitude of the water table illustrates potential ground-water flow directions and areas where ground- and surface-water exchanges and interactions might occur. Water quality measured in selected wells and lakes indicates some differences between ground water and surface water. 'The temporal and spatial scarcity of ground-water-level and water-quality data limits the analysis of flow direction and water quality. Regionally, the water-table map indicates that ground water in the eastern and southern parts of the study area flows southerly. In the northcentral area, ground water flows predominately westerly then southerly. Although ground and surface water in most areas of the Matanuska-Susitna Valley are interconnected, they are chemically different. Analyses of the few water-quality samples collected in the area indicate that dissolved nitrite plus nitrate and orthophosphorus concentrations are higher in ground water than in surface water.'

  15. Microtropography and water table fluctuation in a sphagnum mire

    Science.gov (United States)

    E.S. Verry

    1984-01-01

    A detailed organic soil profile description, 22 years of continuous water table records, and a hummock-hollow level survey were examined at a small Minnesota mire (a bog with remnants of poor fen vegetation). Variation in the level survey suggests that hollows be used to minimize variation when detailed topographic information is needed and to match profile...

  16. Modelling mid-span water table depth and drainage discharge ...

    African Journals Online (AJOL)

    2015-04-03

    Apr 3, 2015 ... were monitored in 1.7 m deep piezometers installed mid-way between two drains by using an electronic .... logical components in soils with shallow water tables. ..... dency of neither under-estimating nor over-estimating DDs,.

  17. Distribution Channel Intensity among Table Water Producers in Nigeria

    Directory of Open Access Journals (Sweden)

    Joseph Edewor Agbadudu

    2017-09-01

    Full Text Available Planning for and making reasonable decisions regarding reaching the target market with an organization’s product is a critical task on the part of management, which involves a careful evaluation and selection of its channel structure and intensity.This study therefore examines distribution channel intensity among table water producers in Edo State, Nigeria. The focus of the study is to ascertain the variables that significantly predict distribution intensity among the firms in the table water industry in Edo State. The study seeks to proffer answer to fundamental question of why brands within a single category of a given consumer good differ significantly in their distribution intensity. Using a survey research design, the data used for this study were obtained by taking a sample of 110 table water firms within the three senatorial districts in the State. The data obtained were presented and analyzed using different statistical tools such as mean and multiple regression through Statistical Packages for Social Sciences (SPSS version 22 software. Findings revealed that manufacturers’ target focus, manufacturers’ support program, brand quality and level of firm’s technological advancement were significant predictors of distribution channel intensity among the industrial players in table water industry in the State. Based on the findings, the study recommended that table water firms within the State can secure a competitive edge over their fellow counterpart in the industry by designing an optimal distribution intensity that will meet up their marketing objectives. It is also recommended that the adoption of modern technology in form of online sales is an efficient way of sales and distribution which could be used to enhance their distribution techniques if there is a need to cut down on middle men due to increased cost. The study concluded that optimal distribution intensity could be achieved not by mere imitation of competitors but through

  18. Woody riparian vegetation response to different alluvial water table regimes

    Science.gov (United States)

    Shafroth, P.B.; Stromberg, J.C.; Patten, D.T.

    2000-01-01

    Woody riparian vegetation in western North American riparian ecosystems is commonly dependent on alluvial groundwater. Various natural and anthropogenic mechanisms can cause groundwater declines that stress riparian vegetation, but little quantitative information exists on the nature of plant response to different magnitudes, rates, and durations of groundwater decline. We observed groundwater dynamics and the response of Populus fremontii, Salix gooddingii, and Tamarix ramosissima saplings at 3 sites between 1995 and 1997 along the Bill Williams River, Arizona. At a site where the lowest observed groundwater level in 1996 (-1.97 m) was 1.11 m lower than that in 1995 (-0.86 m), 92-100% of Populus and Salix saplings died, whereas 0-13% of Tamarix stems died. A site with greater absolute water table depths in 1996 (-2.55 m), but less change from the 1995 condition (0.55 m), showed less Populus and Salix mortality and increased basal area. Excavations of sapling roots suggest that root distribution is related to groundwater history. Therefore, a decline in water table relative to the condition under which roots developed may strand plant roots where they cannot obtain sufficient moisture. Plant response is likely mediated by other factors such as soil texture and stratigraphy, availability of precipitation-derived soil moisture, physiological and morphological adaptations to water stress, and tree age. An understanding of the relationships between water table declines and plant response may enable land and water managers to avoid activities that are likely to stress desirable riparian vegetation.

  19. Future water table rise at Yucca Mountain: A regulatory perspective

    International Nuclear Information System (INIS)

    Coleman, N.M.

    1995-01-01

    The U.S. Nuclear Regulatory Commission staff has developed a program of Systematic Regulatory Analysis (SRA). The purpose of this program is to ensure that important technical issues related to compliance with 10 CFR Part 60 will be identified before receipt of a license application. A plan is being developed to review the U.S. Department of Energy's (DOE's) demonstration of compliance in the license application for each part of the regulation. Under the siting criteria of NRC's Part 60, one of the potentially adverse conditions is the possibility that the water table may rise high enough to saturate a repository in the unsaturated zone. DOE must evaluate this and other conditions in a license application for a geologic repository site. DOE's evaluation must show compliance with the requirements of Part 60 with reasonable assurance. This paper describes the NRC staff's preliminary plans to review DOE's demonstration of compliance, including assumptions about a future rise of the water table

  20. Water tables constrain height recovery of willow on Yellowstone's northern range.

    Science.gov (United States)

    Bilyeu, Danielle M; Cooper, David J; Hobbs, N Thompson

    2008-01-01

    Excessive levels of herbivory may disturb ecosystems in ways that persist even when herbivory is moderated. These persistent changes may complicate efforts to restore ecosystems affected by herbivores. Willow (Salix spp.) communities within the northern range in Yellowstone National Park have been eliminated or degraded in many riparian areas by excessive elk (Cervus elaphus L.) browsing. Elk browsing of riparian willows appears to have diminished following the reintroduction of wolves (Canis lupis L.), but it remains uncertain whether reduced herbivory will restore willow communities. The direct effects of elk browsing on willows have been accompanied by indirect effects from the loss of beaver (Castor canadensis Kuhl) activity, including incision of stream channels, erosion of fine sediments, and lower water tables near streams historically dammed by beaver. In areas where these changes have occurred, lowered water tables may suppress willow height even in the absence of elk browsing. We conducted a factorial field experiment to understand willow responses to browsing and to height of water tables. After four years of protection from elk browsing, willows with ambient water tables averaged only 106 cm in height, with negligible height gain in two of three study species during the last year of the experiment. Willows that were protected from browsing and had artificially elevated water tables averaged 147 cm in height and gained 19 cm in the last year of the experiment. In browsed plots, elevated water tables doubled height gain during a period of slightly reduced browsing pressure. We conclude that water availability mediates the rate of willow height gain and may determine whether willows grow tall enough to escape the browse zone of elk and gain resistance to future elk browsing. Consequently, in areas where long-term beaver absence has resulted in incised stream channels and low water tables, a reduction in elk browsing alone may not be sufficient for recovery

  1. Water table monitoring in a mined riparian zone

    Directory of Open Access Journals (Sweden)

    Thomaz Marques Cordeiro Andrade

    2010-04-01

    Full Text Available The objective of this study was to test an easily fabricated tool that assist in the manual installation of piezometers, as well as water table monitor in the research site, located at the Gualaxo do Norte River Watershed, state of Minas Gerais, Brazil. The tool is made of iron pipes and is a low-cost alternative for shallow groundwater observation wells. The measurements were done in a riparian zone after being gold mined, when vegetation and upper soil layers were removed. The wells were installed in three areas following a transect from the river bank. The method was viable for digging up to its maximum depth of 3 meters in a low resistance soil and can be improved to achieve a better resistance over impact and its maximum depth of perforation. Water table levels varied distinctly according to its depth in each point. It varies most in the more shallow wells in different areas, while it was more stable in the deeper ones. The water table profile reflected the probably profile f the terrain and can be a reference for its leveling in reconstitution of degraded banks where upper layers of the soil were removed. Groundwater monitoring can be also an indicator of the suitability of the substrate for soil reconstitution in terms of the maintenance of an infiltration capacity similar to the original material.

  2. Stochastic analysis of unsaturated steady flows above the water table

    Science.gov (United States)

    Severino, Gerardo; Scarfato, Maddalena; Comegna, Alessandro

    2017-08-01

    Steady flow takes place into a three-dimensional partially saturated porous medium where, due to their spatial variability, the saturated conductivity Ks, and the relative conductivity Kr are modeled as random space functions (RSF)s. As a consequence, the flow variables (FVs), i.e., pressure-head and specific flux, are also RSFs. The focus of the present paper consists into quantifying the uncertainty of the FVs above the water table. The simple expressions (most of which in closed form) of the second-order moments pertaining to the FVs allow one to follow the transitional behavior from the zone close to the water table (where the FVs are nonstationary), till to their far-field limit (where the FVs become stationary RSFs). In particular, it is shown how the stationary limits (and the distance from the water table at which stationarity is attained) depend upon the statistical structure of the RSFs Ks, Kr, and the infiltrating rate. The mean pressure head >> has been also computed, and it is expressed as =Ψ0>(1+ψ>), being ψ a characteristic heterogeneity function which modifies the zero-order approximation Ψ0 of the pressure head (valid for a vadose zone of uniform soil properties) to account for the spatial variability of Ks and Kr. Two asymptotic limits, i.e., close (near field) and away (far field) from the water table, are derived into a very general manner, whereas the transitional behavior of ψ between the near/far field can be determined after specifying the shape of the various input soil properties. Besides the theoretical interest, results of the present paper are useful for practical purposes, as well. Indeed, the model is tested against to real data, and in particular it is shown how it is possible for the specific case study to grasp the behavior of the FVs within an environment (i.e., the vadose zone close to the water table) which is generally very difficult to access by direct inspection.

  3. Changes in vegetative communities and water table dynamics following timber harvesting in small headwater streams

    Science.gov (United States)

    B. Choi; J.C. Dewey; J. A. Hatten; A.W. Ezell; Z. Fan

    2012-01-01

    In order to better understand the relationship between vegetation communities and water table in the uppermost portions (ephemeral–intermittent streams) of headwater systems, seasonal plot-based field characterizations of vegetation were used in conjunction with monthly water table measurements. Vegetation, soils, and water table data were examined to determine...

  4. Water table and overbank flow frequency changes due to suburbanization-induced channel incision, Virginia Coastal Plain, USA

    Science.gov (United States)

    Hancock, G.; Mattell, N.; Christianson, E.; Wacksman, J.

    2004-12-01

    Channel incision is a widely observed response to increased flow in urbanized watersheds, but the effects of channel lowering on riparian water tables is not well documented. In a rapidly incising suburban stream in the Virginia Coastal Plain, we hypothesize that incision has lowered floodplain water tables and decreased the overbank flow frequency, and suggest these changes impact vegetation distribution in a diverse, protected riparian habitat. The monitored stream is a tributary to the James River draining 1.3 km2, of which 15% is impervious cover. Incision has occurred largely through upstream migration of a one m high knickpoint at a rate of 1-2 m/yr, primarily during high flow events. We installed 33 wells in six floodplain transects to assess water table elevations beneath the floodplain adjacent to the incising stream. To document the impacts of incision, two transects are located 30 and 50 m upstream of the knickpoint in unincised floodplain, and the remainder are 5, 30, 70, and 100 m downstream of the knickpoint in incised floodplain. In one transect above and two below, pressure transducers attached to dataloggers provide a high-resolution record of water table response to storm events. Significant differences have been observed in the water table above and below the knickpoint. Above the knickpoint, the water table is relatively flat and is 0.2-0.4 m below the floodplain surface. Water table response to precipitation events is nearly immediate, with the water table rising to the floodplain surface in significant rainfall events. In the transect immediately downstream of the knickpoint, the water table possesses a steep gradient, rising from ~1 m below the floodplain at the stream to 0.3 m below the surface within 20 m. In the most downstream transects, the water table is relatively flat, but is one m below the floodplain surface, equivalent to the depth of incision generated by knickpoint passage. Upstream of the knickpoint, overbank flooding occurs

  5. Links between climate change, water-table depth, and water chemistry in a mineralized mountain watershed

    Science.gov (United States)

    Manning, Andrew H.; Verplanck, Philip L.; Caine, Jonathan S.; Todd, Andrew S.

    2013-01-01

    Recent studies suggest that climate change is causing rising solute concentrations in mountain lakes and streams. These changes may be more pronounced in mineralized watersheds due to the sensitivity of sulfide weathering to changes in subsurface oxygen transport. Specific causal mechanisms linking climate change and accelerated weathering rates have been proposed, but in general remain entirely hypothetical. For mineralized watersheds, a favored hypothesis is that falling water tables caused by declining recharge rates allow an increasing volume of sulfide-bearing rock to become exposed to air, thus oxygen. Here, we test the hypothesis that falling water tables are the primary cause of an increase in metals and SO4 (100-400%) observed since 1980 in the Upper Snake River (USR), Colorado. The USR drains an alpine watershed geologically and climatologically representative of many others in mineralized areas of the western U.S. Hydrologic and chemical data collected from 2005 to 2011 in a deep monitoring well (WP1) at the top of the USR watershed are utilized. During this period, both water table depths and groundwater SO4 concentrations have generally increased in the well. A numerical model was constructed using TOUGHREACT that simulates pyrite oxidation near WP1, including groundwater flow and oxygen transport in both saturated and unsaturated zones. The modeling suggests that a falling water table could produce an increase in metals and SO4 of a magnitude similar to that observed in the USR (up to 300%). Future water table declines may produce limited increases in sulfide weathering high in the watershed because of the water table dropping below the depth of oxygen penetration, but may continue to enhance sulfide weathering lower in the watershed where water tables are shallower. Advective air (oxygen) transport in the unsaturated zone caused by seasonally variable recharge and associated water table fluctuations was found to have little influence on pyrite

  6. Hanford site water table changes 1950-1980: data observations and evaluation

    International Nuclear Information System (INIS)

    Zimmerman, D.A.; Reisenauer, A.E.; Black, G.D.; Young, M.A.

    1986-04-01

    The basalt formations underlying the Hanford site are being considered for characterization and evaluation as a deep geologic repository for defense and commercial radioactive wastes. To understand the hydrology of the Hanford area, we need to know if the ground-water system is in steady state and what impact a change in surface stress from artificial recharge may have on the underlying basalt aquifers. Researchers at Pacific Northwest Laboratory are supporting efforts to understand these issues by illustrating how changes in wastewater disposal activities at the Hanford site have altered the configuration of the water table surface with time. The objective of this work was to determine the magnitude and direction of changes in the elevation of the water table across the Hanford site from 1950 to 1980. Plots of the magnitudes of water-level changes occurring over 5-year intervals from 1950 through 1980 are presented. The water-level changes that occurred during each 5-year interval are related to water discharges from nuclear fuel reprocessing facilities or other discharge sources. The plots of water-level changes show large water-level increases in the vicinity of the Separations Area (200 East and 200 West) from 1950 to 1960; the rate of increase of water-level changes grows more slowly from 1960 to 1970, while the areal extent of the mounding continues to expand. Only small changes occur from 1970 to 1980; during this time period, the unconfined system appears to be in approximate equilibrium with the sources. Based on previous experience, it is believed that an increase in ground-water mounding will begin to appear near the 200 East Area B Pond as a result of the increased discharges from the restart of PUREX in 1983

  7. African Mahogany transpiration with Granier method and water table lysimeter

    Directory of Open Access Journals (Sweden)

    Ana C. O. Sérvulo

    Full Text Available ABSTRACT The thermal dissipation probe (Granier method is useful in the water deficit monitoring and irrigation management of African Mahogany, but its model needs proper adjustment. This paper aimed to adjust and validate the Granier sap flux model to estimate African Mahogany transpiration, measure transpiration using lysimeter and relate it to atmospheric water demand. Weather conditions, transpiration and sap flux were monitored in three units of 2.5-year-old African Mahogany trees in constant water table lysimeter, in Goiânia, GO. Sapwood area (SA, leaf area (LA, transpiration measured by lysimeter (TLYS and estimated by sap flux (TSF were evaluated. The SA comprised 55.24% of the trunk’s transversal section. The LA varied from 11.95 to 10.66 m2. TLYS and TSF varied from 2.94 to 29.31 and from 0.94 to 15.45 L d-1, respectively. The original model underestimated transpiration by 44.4%, being the adjusted equation F = 268.25 . k1.231. SA was significant (F < 0.05. Due the root confinement, the transpiration showed low correlation, but positive, with the atmospheric water demand.

  8. Optimization of irrigation water in stone fruit and table grapes

    Science.gov (United States)

    de la Rosa, Jose Mª; Castillo, Cristina; Temnani, Abdel; Pérez-Pastor, Alejandro

    2017-04-01

    In water scarcity areas, it must be highlighted that the maximum productions of the crops do not necessarily imply maximum profitability. Therefore, during the last years a special interest in the development of deficit irrigation strategies based on significant reductions of the seasonal ET without affecting production or quality has been observed. The strategies of regulated deficit irrigation (RDI) are based on the reduction of water supply during non critical periods, the covering of water needs during critical periods and maximizing, at the same time, the production by unit of applied water. The main objective of this experiment was to implement, demonstrate and disseminate a sustainable irrigation strategy based on deficit irrigation to promote its large scale acceptance and use in woody crops in Mediterranean agroecosystems, characterized by water scarcity, without affecting the quality standards demanded by exportation markets. Five demonstration plots were established in representative crops of the irrigating community of Campotejar (Murcia, Spain): i) Peach trees, cv. catherina in the "Periquitos" farm; ii) Apricot trees, cv. "Red Carlet" in "La Hoya del Fenazar" farm; iii) Nectarine trees, cv. Viowhite in "Agrícola Don Fernando" farm; iv) Table grape, cv "Crimson Seedless" in "La Hornera" farm; and v) Paraguayan cv. carioca in "The Hornera" farm. In each demonstration plot, at least two irrigation treatments were established: i) Control (CTL), irrigated to ensure non-limiting water conditions (120% of crop evapotranspiration) and ii) Regulated deficit irrigation (RDI) irrigated as CTL during critical periods and decreasing irrigation in non-critical periods. The plant water status indicators evaluated were midday stem water potential and Trunk Diameter Fluctuation derived indices: maximum daily shrinkage (MDS) and trunk daily growth rate (TGR); vegetative growth of the different crops from trunk diameter and pruning dry weight, fruit growth and fruit

  9. Modelling contrasting responses of wetland productivity to changes in water table depth

    Directory of Open Access Journals (Sweden)

    R. F. Grant

    2012-11-01

    Full Text Available Responses of wetland productivity to changes in water table depth (WTD are controlled by complex interactions among several soil and plant processes, and hence are site-specific rather than general in nature. Hydrological controls on wetland productivity were studied by representing these interactions in connected hummock and hollow sites in the ecosystem model ecosys, and by testing CO2 and energy fluxes from the model with those measured by eddy covariance (EC during years with contrasting WTD in a shrub fen at Lost Creek, WI. Modelled interactions among coupled processes for O2 transfer, O2 uptake, C oxidation, N mineralization, N uptake and C fixation by diverse microbial, root and mycorrhizal populations enabled the model to simulate complex responses of CO2 exchange to changes in WTD that depended on the WTD at which change was occurring. At the site scale, greater WTD caused the model to simulate greater CO2 influxes and effluxes over hummocks vs. hollows, as has been found at field sites. At the landscape scale, greater WTD caused the model to simulate greater diurnal CO2 influxes and effluxes under cooler weather when water tables were shallow, but also smaller diurnal CO2 influxes and effluxes under warmer weather when water tables were deeper, as was also apparent in the EC flux measurements. At an annual time scale, these diurnal responses to WTD in the model caused lower net primary productivity (NPP and heterotrophic respiration (Rh, but higher net ecosystem productivity (NEP = NPP − Rh, to be simulated in a cooler year with a shallower water table than in a warmer year with a deeper one. This difference in NEP was consistent with those estimated from gap-filled EC fluxes in years with different water tables at Lost Creek and at similar boreal fens elsewhere. In sensitivity tests of the model, annual NEP

  10. Radar sounding of bedrock and water table at Chalk River

    International Nuclear Information System (INIS)

    Annan, A.P.; Davis, J.L.

    1979-01-01

    When a spill of radioactive waste occurs, one of the main concerns is the flow pattern of ground water in the area of the spill. Ground probing radar is a relatively new geophysical technique which can provide high resolution data on the surficial geology and water distribution. The results of some preliminary radar experiments conducted at Chalk River Nuclear Laboratories (CRNL) of the Atomic Energy of Canada Limited (AECL), Chalk River, Ontario are presented. (auth)

  11. A time series approach to inferring groundwater recharge using the water table fluctuation method

    Science.gov (United States)

    Crosbie, Russell S.; Binning, Philip; Kalma, Jetse D.

    2005-01-01

    The water table fluctuation method for determining recharge from precipitation and water table measurements was originally developed on an event basis. Here a new multievent time series approach is presented for inferring groundwater recharge from long-term water table and precipitation records. Additional new features are the incorporation of a variable specific yield based upon the soil moisture retention curve, proper accounting for the Lisse effect on the water table, and the incorporation of aquifer drainage so that recharge can be detected even if the water table does not rise. A methodology for filtering noise and non-rainfall-related water table fluctuations is also presented. The model has been applied to 2 years of field data collected in the Tomago sand beds near Newcastle, Australia. It is shown that gross recharge estimates are very sensitive to time step size and specific yield. Properly accounting for the Lisse effect is also important to determining recharge.

  12. OCCURANCE OF POLYCYCLIC AROMATIC HYDROCARBONS IN SUPRAŚL WATERS

    Directory of Open Access Journals (Sweden)

    Joanna Struk-Sokołowska

    2014-11-01

    Full Text Available The paper discusses the results of studies conducted in 2011 and 2012, including the presence of five polycyclc aromatic hydrocarbons. Their limits are determined by Regulation of the Minister of the Environment dated 9 November 2011. Have been analyzed benzo (a pyrene, benzo (b fuoranthene, benzo (k fuoranthene, benzo (g, h, i perylene and indeno (1,2,3-cd perylene. Water samples were taken to the nearby town of Nowodworce. Taken markings quantitative-qualitative / the substance. In addition, the average was calculated loads studied ingredients. The highest total concentration of PAHs was recorded in 2011, but it does not exceed the limit values. The following year, it was much lower.

  13. Reducing nitrate loss in tile drainage water with cover crops and water-table management systems.

    Science.gov (United States)

    Drury, C F; Tan, C S; Welacky, T W; Reynolds, W D; Zhang, T Q; Oloya, T O; McLaughlin, N B; Gaynor, J D

    2014-03-01

    Nitrate lost from agricultural soils is an economic cost to producers, an environmental concern when it enters rivers and lakes, and a health risk when it enters wells and aquifers used for drinking water. Planting a winter wheat cover crop (CC) and/or use of controlled tile drainage-subirrigation (CDS) may reduce losses of nitrate (NO) relative to no cover crop (NCC) and/or traditional unrestricted tile drainage (UTD). A 6-yr (1999-2005) corn-soybean study was conducted to determine the effectiveness of CC+CDS, CC+UTD, NCC+CDS, and NCC+UTD treatments for reducing NO loss. Flow volume and NO concentration in surface runoff and tile drainage were measured continuously, and CC reduced the 5-yr flow-weighted mean (FWM) NO concentration in tile drainage water by 21 to 38% and cumulative NO loss by 14 to 16% relative to NCC. Controlled tile drainage-subirrigation reduced FWM NO concentration by 15 to 33% and cumulative NO loss by 38 to 39% relative to UTD. When CC and CDS were combined, 5-yr cumulative FWM NO concentrations and loss in tile drainage were decreased by 47% (from 9.45 to 4.99 mg N L and from 102 to 53.6 kg N ha) relative to NCC+UTD. The reductions in runoff and concomitant increases in tile drainage under CC occurred primarily because of increases in near-surface soil hydraulic conductivity. Cover crops increased corn grain yields by 4 to 7% in 2004 increased 3-yr average soybean yields by 8 to 15%, whereas CDS did not affect corn or soybean yields over the 6 yr. The combined use of a cover crop and water-table management system was highly effective for reducing NO loss from cool, humid agricultural soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  14. Water-table fluctuations in the Amargosa Desert, Nye County, Nevada

    International Nuclear Information System (INIS)

    Paces, James B.; Whelan, Joseph

    2001-01-01

    Pleistocene ground-water discharge deposits approximately 20 km southwest of Yucca Mountain were previously thought to represent pluvial water-table rises of 80 to 120 m. Data from new boreholes at two of the three discharge sites indicate that the modern water-table is at depths of only 17 to 30 m and that this shallow water is part of the regional ground-water flow system rather than being perched. Calcite in equilibrium with this modern ground water would have isotopic compositions similar to those in Pleistocene calcite associated with the discharge deposits. Carbon and uranium isotopes in both ground water and discharge deposits imply that past discharge consisted of a mixture of both shallow and deep ground water. These data limit Pleistocene water-table fluctuations at the specified Amargosa Desert discharge sites to between 17 and 30 m and eliminate the need to invoke large water-table rises

  15. Numerical tables on physical and chemical analyses of Rhine water

    International Nuclear Information System (INIS)

    1982-01-01

    Tables on the places of measurement, the sampling methods and the methods of analysis used. The numerical tables of the measurement results are broken down in general parameters, organic, entrophicating and anorganic substances, orgnic micro-pollutants and radioactivity. (GG) [de

  16. Response of anaerobic carbon cycling to water table manipulation in an Alaskan rich fen

    Science.gov (United States)

    E.S. Kane; M.R. Chivers; M.S. Turetsky; C.C. Treat; D.G. Petersen; M. Waldrop; J.W. Harden; A.D. McGuire

    2013-01-01

    To test the effects of altered hydrology on organic soil decomposition, we investigated CO2 and CH4 production potential of rich-fen peat (mean surface pH = 6.3) collected from a field water table manipulation experiment including control, raised and lowered water table treatments. Mean anaerobic CO2...

  17. Ground Water Recharge Estimation Using Water Table Fluctuation Method And By GIS Applications

    Science.gov (United States)

    Vajja, V.; Bekkam, V.; Nune, R.; M. v. S, R.

    2007-05-01

    Quite often it has become a debating point that how much recharge is occurring to the groundwater table through rainfall on one hand and through recharge structures such as percolation ponds and checkdams on the other. In the present investigations Musi basin of Andhra Pradesh, India is selected for study during the period 2005-06. Pre-monsoon and Post-monsoon groundwater levels are collected through out the Musi basin at 89 locations covering an area11, 291.69 km2. Geology of the study area and rainfall data during the study period has been collected. The contour maps of rainfall and the change in groundwater level between Pre-monsoon and Post- monsoon have been prepared. First the change in groundwater storage is estimated for each successive strips of areas enclosed between two contours of groundwater level fluctuations. In this calculation Specific yield (Sy) values are adopted based on the local Geology. Areas between the contours are estimated through Arc GIS software package. All such storages are added to compute the total storage for the entire basin. In order to find out the percent of rainfall converted into groundwater storage as well as to find out the ground water recharge due to storageponds, a contour map of rainfall for the study area is prepared and areas between successive contours have been calculated. Based on the Geology map, Infiltration values are adopted for each successive strip of the contour area. Then the amount of water infiltrated into the ground is calculated by adjusting the infiltration values for each strip, so that the total infiltrated water for the entire basin is matched with change in Ground water storage, which is 1314.37 MCM for the upper Musi basin while it is 2827.29 MCM for entire Musi basin. With this procedure on an average 29.68 and 30.66 percent of Rainfall is converted into Groundwater recharge for Upper Musi and for entire Musi basin respectively. In the total recharge, the contribution of rainfall directly to

  18. Discoloration of polyvinyl chloride (PVC) tape as a proxy for water-table depth in peatlands: validation and assessment of seasonal variability

    Science.gov (United States)

    Booth, Robert K.; Hotchkiss, Sara C.; Wilcox, Douglas A.

    2005-01-01

    Summary: 1. Discoloration of polyvinyl chloride (PVC) tape has been used in peatland ecological and hydrological studies as an inexpensive way to monitor changes in water-table depth and reducing conditions. 2. We investigated the relationship between depth of PVC tape discoloration and measured water-table depth at monthly time steps during the growing season within nine kettle peatlands of northern Wisconsin. Our specific objectives were to: (1) determine if PVC discoloration is an accurate method of inferring water-table depth in Sphagnum-dominated kettle peatlands of the region; (2) assess seasonal variability in the accuracy of the method; and (3) determine if systematic differences in accuracy occurred among microhabitats, PVC tape colour and peatlands. 3. Our results indicated that PVC tape discoloration can be used to describe gradients of water-table depth in kettle peatlands. However, accuracy differed among the peatlands studied, and was systematically biased in early spring and late summer/autumn. Regardless of the month when the tape was installed, the highest elevations of PVC tape discoloration showed the strongest correlation with midsummer (around July) water-table depth and average water-table depth during the growing season. 4. The PVC tape discoloration method should be used cautiously when precise estimates are needed of seasonal changes in the water-table.

  19. Water table in Long Island, New York, March 1971

    Science.gov (United States)

    Koszalka, Edward J.; Koch, Ellis

    1971-01-01

    The geologic framework and the hydrologic situation in Long Island are periodically reviewed by the U.S. Geological Survey as new knowledge is obtained from current investigations. This work is done through cooperative programs with Nassau and Suffolk County agencies and the New York State Department of Environmental Conservation. A unique opportunity to update many of the hydrogeologic maps occurred when the Geological Survey's Mineola, N.Y., office participated in the New England River Basins Commission's "Long Island Sound Study." This map, one of a series of open-file maps showing the updated information, was compiled from data obtained from G. E. Kimmel (written commun., July 1972) and Jensen and Soren (in press). Comparison of the March 1971 data with similar data for March 1970 (Kimmel, 1970) shows virtually no change in water levels on Long Island during the 12 month period, except for a slight decline in levels in central Suffolk County.

  20. Numerical tables on physical and chemical analyses of Rhine water 1983

    International Nuclear Information System (INIS)

    1984-01-01

    The numerical tables contain the measuring results of the physical-chemical studies on the Rhine water for the year 1983. The tables are arranged by general parameters, organic matter, eutrophicating substances, anorganic matter, metals, organic micropollution as well as by radioactivity (total alpha- or beta- and T-activity). (MM) [de

  1. Developing Automatic Water Table Control System for Reducing Greenhouse Gas Emissions from Paddy Fields

    Science.gov (United States)

    Arif, C.; Fauzan, M. I.; Satyanto, K. S.; Budi, I. S.; Masaru, M.

    2018-05-01

    Water table in rice fields play important role to mitigate greenhouse gas (GHG) emissions from paddy fields. Continuous flooding by maintenance water table 2-5 cm above soil surface is not effective and release more GHG emissions. System of Rice Intensification (SRI) as alternative rice farming apply intermittent irrigation by maintaining lower water table is proven can reduce GHG emissions reducing productivity significantly. The objectives of this study were to develop automatic water table control system for SRI application and then evaluate the performances. The control system was developed based on fuzzy logic algorithms using the mini PC of Raspberry Pi. Based on laboratory and field tests, the developed system was working well as indicated by lower MAPE (mean absolute percentage error) values. MAPE values for simulation and field tests were 16.88% and 15.80%, respectively. This system can save irrigation water up to 42.54% without reducing productivity significantly when compared to manual irrigation systems.

  2. Water table fluctuations and soil biogeochemistry: An experimental approach using an automated soil column system

    Science.gov (United States)

    Rezanezhad, F.; Couture, R.-M.; Kovac, R.; O'Connell, D.; Van Cappellen, P.

    2014-02-01

    Water table fluctuations significantly affect the biological and geochemical functioning of soils. Here, we introduce an automated soil column system in which the water table regime is imposed using a computer-controlled, multi-channel pump connected to a hydrostatic equilibrium reservoir and a water storage reservoir. The potential of this new system is illustrated by comparing results from two columns filled with 45 cm of the same homogenized riparian soil. In one soil column the water table remained constant at -20 cm below the soil surface, while in the other the water table oscillated between the soil surface and the bottom of the column, at a rate of 4.8 cm d-1. The experiment ran for 75 days at room temperature (25 ± 2 °C). Micro-sensors installed at -10 and -30 cm below the soil surface in the stable water table column recorded constant redox potentials on the order of 600 and -200 mV, respectively. In the fluctuating water table column, redox potentials at the same depths oscillated between oxidizing (∼700 mV) and reducing (∼-100 mV) conditions. Pore waters collected periodically and solid-phase analyses on core material obtained at the end of the experiment highlighted striking geochemical differences between the two columns, especially in the time series and depth distributions of Fe, Mn, K, P and S. Soil CO2 emissions derived from headspace gas analysis exhibited periodic variations in the fluctuating water table column, with peak values during water table drawdown. Transient redox conditions caused by the water table fluctuations enhanced microbial oxidation of soil organic matter, resulting in a pronounced depletion of particulate organic carbon in the midsection of the fluctuating water table column. Denaturing Gradient Gel Electrophoresis (DGGE) revealed the onset of differentiation of the bacterial communities in the upper (oxidizing) and lower (reducing) soil sections, although no systematic differences in microbial community structure

  3. Contribution of vegetation and water table on isoprene emission from boreal peatland microcosms

    DEFF Research Database (Denmark)

    Tiiva, Päivi; Faubert, Patrick; Räty, Sanna

    2009-01-01

    emission in these naturally wet ecosystems, although water table is predicted to decline due to climate warming. We studied the relative contribution of mosses vs. vascular plants to isoprene emission in boreal peatland microcosms in growth chambers by removing either vascular vegetation or both vascular...... hollows with intact vegetation, 45 ± 6 µg m-2 h-1, was decreased by 25% under water table drawdown. However, water table drawdown reduced net ecosystem carbon dioxide (CO2) exchange more dramatically than isoprene emission. Isoprene emission strongly correlated with both CO2 exchange and methane emission......Boreal peatlands are substantial sources of isoprene, a reactive hydrocarbon. However, it is not known how much mosses, vascular plants and peat each contribute to isoprene emission from peatlands. Furthermore, there is no information on the effects of declining water table depth on isoprene...

  4. Diffusive-dispersive mass transfer in the capillary fringe: Impact of water table fluctuations and heterogeneities

    DEFF Research Database (Denmark)

    Grathwohl, Peter; Haberer, Cristina; Ye, Yu

    Diffusive–dispersive mass transfer in the capillary fringe is important for many groundwater quality issues such as transfer of volatile compounds into (and out of) the groundwater, the supply of oxygen for aerobic degradation of hydrocarbons as well as for precipitation of minerals (e.g. iron...... hydroxides). 2D-laboratory scale experiments were used to investigate the transfer of oxygen into groundwater under non-reactive and reactive conditions, at steady state and with water table fluctuations. Results show that transfer of oxygen is limited by transverse dispersion in the capillary fringe...... and the dispersion coefficients are the same as below the water table. Water table fluctuations cause temporarily increased fluxes of oxygen into groundwater during draining conditions and entrapped air after water table rise. High-permeability inclusions in the capillary fringe enhance mass transfer of oxygen...

  5. Water property lookup table (sanwat) for use with the two-phase computational code shaft

    International Nuclear Information System (INIS)

    Sherman, M.P.; Eaton, R.R.

    1980-10-01

    A lookup table for water thermodynamic and transport properties (SANWAT) has been constructed for use with the two-phase computational code, SHAFT. The table, which uses density and specific internal energy as independent variables, covers the liquid, two-phase, and vapor regions. The liquid properties of water are contained in a separate subtable in order to obtain high accuracy for this nearly incompressible region that is frequently encountered in studies of the characteristics of nuclear-waste repositories

  6. Water table tests of proposed heat transfer tunnels for small turbine vanes

    Science.gov (United States)

    Meitner, P. L.

    1974-01-01

    Water-table flow tests were conducted for proposed heat-transfer tunnels which were designed to provide uniform flow into their respective test sections of a single core engine turbine vane and a full annular ring of helicopter turbine vanes. Water-table tests were also performed for the single-vane test section of the core engine tunnel. The flow in the heat-transfer tunnels was shown to be acceptable.

  7. Moderate drop in water table increases peatland vulnerability to post-fire regime shift.

    Science.gov (United States)

    Kettridge, N; Turetsky, M R; Sherwood, J H; Thompson, D K; Miller, C A; Benscoter, B W; Flannigan, M D; Wotton, B M; Waddington, J M

    2015-01-27

    Northern and tropical peatlands represent a globally significant carbon reserve accumulated over thousands of years of waterlogged conditions. It is unclear whether moderate drying predicted for northern peatlands will stimulate burning and carbon losses as has occurred in their smaller tropical counterparts where the carbon legacy has been destabilized due to severe drainage and deep peat fires. Capitalizing on a unique long-term experiment, we quantify the post-wildfire recovery of a northern peatland subjected to decadal drainage. We show that the moderate drop in water table position predicted for most northern regions triggers a shift in vegetation composition previously observed within only severely disturbed tropical peatlands. The combined impact of moderate drainage followed by wildfire converted the low productivity, moss-dominated peatland to a non-carbon accumulating shrub-grass ecosystem. This new ecosystem is likely to experience a low intensity, high frequency wildfire regime, which will further deplete the legacy of stored peat carbon.

  8. Enhancing Groundwater Cost Estimation with the Interpolation of Water Tables across the United States

    Science.gov (United States)

    Rosli, A. U. M.; Lall, U.; Josset, L.; Rising, J. A.; Russo, T. A.; Eisenhart, T.

    2017-12-01

    Analyzing the trends in water use and supply across the United States is fundamental to efforts in ensuring water sustainability. As part of this, estimating the costs of producing or obtaining water (water extraction) and the correlation with water use is an important aspect in understanding the underlying trends. This study estimates groundwater costs by interpolating the depth to water level across the US in each county. We use Ordinary and Universal Kriging, accounting for the differences between aquifers. Kriging generates a best linear unbiased estimate at each location and has been widely used to map ground-water surfaces (Alley, 1993).The spatial covariates included in the universal Kriging were land-surface elevation as well as aquifer information. The average water table is computed for each county using block kriging to obtain a national map of groundwater cost, which we compare with survey estimates of depth to the water table performed by the USDA. Groundwater extraction costs were then assumed to be proportional to water table depth. Beyond estimating the water cost, the approach can provide an indication of groundwater-stress by exploring the historical evolution of depth to the water table using time series information between 1960 and 2015. Despite data limitations, we hope to enable a more compelling and meaningful national-level analysis through the quantification of cost and stress for more economically efficient water management.

  9. Stochastic estimation of plant-available soil water under fluctuating water table depths

    Science.gov (United States)

    Or, Dani; Groeneveld, David P.

    1994-12-01

    Preservation of native valley-floor phreatophytes while pumping groundwater for export from Owens Valley, California, requires reliable predictions of plant water use. These predictions are compared with stored soil water within well field regions and serve as a basis for managing groundwater resources. Soil water measurement errors, variable recharge, unpredictable climatic conditions affecting plant water use, and modeling errors make soil water predictions uncertain and error-prone. We developed and tested a scheme based on soil water balance coupled with implementation of Kalman filtering (KF) for (1) providing physically based soil water storage predictions with prediction errors projected from the statistics of the various inputs, and (2) reducing the overall uncertainty in both estimates and predictions. The proposed KF-based scheme was tested using experimental data collected at a location on the Owens Valley floor where the water table was artificially lowered by groundwater pumping and later allowed to recover. Vegetation composition and per cent cover, climatic data, and soil water information were collected and used for developing a soil water balance. Predictions and updates of soil water storage under different types of vegetation were obtained for a period of 5 years. The main results show that: (1) the proposed predictive model provides reliable and resilient soil water estimates under a wide range of external conditions; (2) the predicted soil water storage and the error bounds provided by the model offer a realistic and rational basis for decisions such as when to curtail well field operation to ensure plant survival. The predictive model offers a practical means for accommodating simple aspects of spatial variability by considering the additional source of uncertainty as part of modeling or measurement uncertainty.

  10. Estimating steady-state evaporation rates from bare soils under conditions of high water table

    Science.gov (United States)

    Ripple, C.D.; Rubin, J.; Van Hylckama, T. E. A.

    1970-01-01

    A procedure that combines meteorological and soil equations of water transfer makes it possible to estimate approximately the steady-state evaporation from bare soils under conditions of high water table. Field data required include soil-water retention curves, water table depth and a record of air temperature, air humidity and wind velocity at one elevation. The procedure takes into account the relevant atmospheric factors and the soil's capability to conduct 'water in liquid and vapor forms. It neglects the effects of thermal transfer (except in the vapor case) and of salt accumulation. Homogeneous as well as layered soils can be treated. Results obtained with the method demonstrate how the soil evaporation rates·depend on potential evaporation, water table depth, vapor transfer and certain soil parameters.

  11. Geostatistical investigation into the temporal evolution of spatial structure in a shallow water table

    Directory of Open Access Journals (Sweden)

    S. W. Lyon

    2006-01-01

    Full Text Available Shallow water tables near-streams often lead to saturated, overland flow generating areas in catchments in humid climates. While these saturated areas are assumed to be principal biogeochemical hot-spots and important for issues such as non-point pollution sources, the spatial and temporal behavior of shallow water tables, and associated saturated areas, is not completely understood. This study demonstrates how geostatistical methods can be used to characterize the spatial and temporal variation of the shallow water table for the near-stream region. Event-based and seasonal changes in the spatial structure of the shallow water table, which influences the spatial pattern of surface saturation and related runoff generation, can be identified and used in conjunction to characterize the hydrology of an area. This is accomplished through semivariogram analysis and indicator kriging to produce maps combining soft data (i.e., proxy information to the variable of interest representing general shallow water table patterns with hard data (i.e., actual measurements that represent variation in the spatial structure of the shallow water table per rainfall event. The area used was a hillslope in the Catskill Mountains region of New York State. The shallow water table was monitored for a 120 m×180 m near-stream region at 44 sampling locations on 15-min intervals. Outflow of the area was measured at the same time interval. These data were analyzed at a short time interval (15 min and at a long time interval (months to characterize the changes in the hydrologic behavior of the hillslope. Indicator semivariograms based on binary-transformed ground water table data (i.e., 1 if exceeding the time-variable median depth to water table and 0 if not were created for both short and long time intervals. For the short time interval, the indicator semivariograms showed a high degree of spatial structure in the shallow water table for the spring, with increased range

  12. Study of energy transfer in table-top X-pinch driven by a water line

    International Nuclear Information System (INIS)

    Beg, F N; Zhang, T; Fedin, D; Beagen, B; Chua, E; Lee, J Y; Rawat, R S; Lee, P

    2007-01-01

    The current passing through X-pinches and the energy transferring from the pulse forming line to the load are modelled using a simple LCR circuit. A comparison of the electrical properties of two table-top X-pinch devices is made. It was found that up to 25% of the stored energy is transferred from the water transmission line to the load in the University of California,San Diego (UCSD) table-top X-pinch before x-ray emission starts. The highest energy transmitted (75%) is found after the current peak. In comparison, only 3% of the energy is transferred to the load in the National Institute of Education (NIE) X-pinch device just after the maximum current peak. The highest energy (25%) transmitted to the plasma occurs long after the current peak. The plasma in both devices is visually and qualitatively similar. However, the UCSD device emits intense x-rays with no x-rays observed in the NIE device. This observation is consistent with the electrical circuit analysis

  13. Physiological strategies of co-occurring oaks in a water- and nutrient-limited ecosystem

    Science.gov (United States)

    Heidi Renninger; Nicholas Carlo; Kenneth L. Clark; Karina V.R. Schafer

    2014-01-01

    Oak species are well suited to water-limited conditions by either avoiding water stress through deep rooting or tolerating water stress through tight stomatal control. In co-occurring species where resources are limited, species may either partition resources in space and/or time or exhibit differing efficiencies in the use of limited resources. Therefore, this study...

  14. Influence of the tension-saturated zone on contaminant migration in shallow water-table regimes

    International Nuclear Information System (INIS)

    Gillham, R.W.

    1982-01-01

    Groundwater discharge represents a major pathway for the return to the biosphere of contaminants that are released to the subsurface environment. An understanding of the transport processes in groundwater discharge zones is therefore an important consideration in pathway analyses associated with the environmental assessment of proposed waste-management facilities. Shallow water tables are a common characteristic of groundwater discharge zones, particularly in humid climatic regions. In this paper, the results of field tests, laboratory tests and numerical simulations are used to show that under shallow water-table conditions, the zone of tension saturation can result in a rapid and highly disproportionate water-table response to precipitation. It is further shown that this response can result in complex migration patterns that would not be predicted by the classical approaches to solute transport modelling and that the response could result in large and highly transient inputs to surface water

  15. Water laws in eleven midwestern states: summary tables

    Energy Technology Data Exchange (ETDEWEB)

    McNeil, T.L.; Torpy, M.F.

    1979-06-01

    Basic information about the water laws of Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Ohio, and West Virginia is summarized. References to state laws and court decisions that may be useful in assessing the legal availability of water for energy development are provided. (MCW)

  16. Energy balance concept in the evaluation of water table management effects on corn growth: experimental investigation

    International Nuclear Information System (INIS)

    Kalita, P.K.; Kanwar, R.S.

    1992-01-01

    The effects of water table management practices (WTMP) on corn growth in 1989 and 1990 at two field sites, Ames and Ankeny, Iowa, were evaluated by calculating crop water stress index (CWSI) and monitoring plant physiological parameters during the growing seasons. Experiments were conducted on field lysimeters at the Ames site by maintaining water tables at 0.3-, 0.6-, and 0.9-m depths and in a subirrigation field at the Ankeny site with 0.2-, 0.3-, 0.6-, 0.9-, and 1.1-m water table depths, and periodically measuring leaf and air temperature, transpiration rate, stomatal conductance, and photosynthetically active radiation (PAR) using leaf chamber techniques. Net radiation of canopy was estimated using the leaf energy balance equation and leaf chamber measurements and then correlated with PAR. Analysis of data revealed that net radiation, leaf air temperature differential, transpiration rate, stomatal conductance, and CWSI were strongly related to WTMP during vegetative and flowering stages of corn growth. Excess water in the root zone with a water table depth of 0.2 m caused the maximum crop water stress and ceased crop growth. Both water and oxygen could be adequately maintained for favorable crop growth by adopting the best WTMP. Results indicate that plant physiological parameters and CWSI could be used to evaluate the effectiveness of WTMP and develop the best WTMP for corn growth in the humid region

  17. Model evaluation of seepage from uranium tailings disposal above and below the water table

    International Nuclear Information System (INIS)

    Nelson, R.W.; Meyer, P.R.; Oberlander, P.L.; Sneider, S.C.; Mayer, D.W.; Reisenauer, A.E.

    1983-03-01

    Model simulations identify the rate and amount of leachate released to the environment if disposed uranium mill tailings come into contact with ground water or if seepage from tailings reaches ground water. In this study, simulations of disposal above and below the water table, with various methods of leachate control, were compared. Three leachate control methods were used in the comparisons: clay bottom liners; stub-sidewall clay liners; and tailings drains with sumps, with the effluent pumped back from the sumps. The best leachate control for both above and below the water table is a combination of the three methods. The combined methods intercept up to 80% of the leachate volume in pits above the water table and intercept essentially all of the leachate in pits below the water table. Effluent pumping, however, requires continuous energy costs and an alternative method of disposal for the leachate that cannot be reused as makeup water in the mill process. Without the drains or effluent pumping, the clay bottom liners have little advantage in terms of the total volume of leachate lost. The clay liners do reduce the rate of leachate flow to the ground water, but the flow continues for a longer time. The buffering, sorption, and chemical reactions of the leachate passing directly through the liner are also advantages of the liner

  18. Dynamics of leaf water relations components in co-occurring iso- and anisohydric conifer species

    Science.gov (United States)

    Frederick Meinzer; David Woodruff; Danielle Marias; Katherine McCulloh; Sanna Sevanto

    2014-01-01

    Because iso- and anisohydric species differ in stomatal regulation of the rate and magnitude of fluctuations in shoot water potential, they may be expected to show differences in the plasticity of their shoot water relations components, but explicit comparisons of this nature have rarely been made. We subjected excised shoots of co-occurring anisohydric Juniperus...

  19. Combined uses of water-table fluctuation (WTF), chloride mass ...

    African Journals Online (AJOL)

    Agadaga

    isotopes methods to investigate groundwater recharge ... and isotopic characterization of groundwater, rainfall and the unsaturated zone were also carried out using a ..... Chloride concentrations in soil water extracted by lixiviation from.

  20. Environmental isotope profiles and evaporation in shallow water table soils

    International Nuclear Information System (INIS)

    Hussein, M.F.; Froehlich, K.; Nada, A.

    2001-01-01

    Environmental isotope methods have been employed to evaluate the processes of evaporation and soil salinisation in the Nile Delta. Stable isotope profiles (δ 18 O and δ 2 H) from three sites were analysed using a published isothermal model that analyses the steady-state isotopic profile in the unsaturated zone and provides an estimate of the evaporation rate. Evaporation rates estimated by this method at the three sites range between 60 and 98 mm y -1 which translates to an estimate of net water loss of one billion cubic meters per year from fallow soils on the Nile delta. Capillary rise of water through the root zone during the crop growing season is estimated to be three times greater than evaporation rate estimate and a modified water management strategy could be adopted in order to optimize water use and its management on the regional scale. (author)

  1. Water table lowering to improve excavation performance and to reduce acid mine drainage

    International Nuclear Information System (INIS)

    Koppe, J.C.; Costa, J.F.; Laurent, O. Jr.

    1995-01-01

    This paper analyses the water table level fluctuations using wells located adjacent to the stripping cuts at the Butia-Leste coal mine, southernmost of Brazil. Piezometers monitored the water table fluctuations. Geological mapping provided additional information aiding the interpretation of the results. A contouring software was also used as tool to aid the interpretation of the data and the results visualisation. The parameters necessary in selecting the location of the wells and pumping volumes were calculated from the data obtained in the water table lowering tests. The results were used to minimise two main problems: the generation of acid mine drainage and the reduction of the excavation performance of the fleet used in overburden removal. 7 refs., 5 figs., 3 tabs

  2. Estimating drain flow from measured water table depth in layered soils under free and controlled drainage

    Science.gov (United States)

    Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

    2018-01-01

    Long records of continuous drain flow are important for quantifying annual and seasonal changes in the subsurface drainage flow from drained agricultural land. Missing data due to equipment malfunction and other challenges have limited conclusions that can be made about annual flow and thus nutrient loads from field studies, including assessments of the effect of controlled drainage. Water table depth data may be available during gaps in flow data, providing a basis for filling missing drain flow data; therefore, the overall goal of this study was to examine the potential to estimate drain flow using water table observations. The objectives were to evaluate how the shape of the relationship between drain flow and water table height above drain varies depending on the soil hydraulic conductivity profile, to quantify how well the Hooghoudt equation represented the water table-drain flow relationship in five years of measured data at the Davis Purdue Agricultural Center (DPAC), and to determine the impact of controlled drainage on drain flow using the filled dataset. The shape of the drain flow-water table height relationship was found to depend on the selected hydraulic conductivity profile. Estimated drain flow using the Hooghoudt equation with measured water table height for both free draining and controlled periods compared well to observed flow with Nash-Sutcliffe Efficiency values above 0.7 and 0.8 for calibration and validation periods, respectively. Using this method, together with linear regression for the remaining gaps, a long-term drain flow record for a controlled drainage experiment at the DPAC was used to evaluate the impacts of controlled drainage on drain flow. In the controlled drainage sites, annual flow was 14-49% lower than free drainage.

  3. Influence of water table decline on growth allocation and endogenous gibberellins in black cottonwood

    Energy Technology Data Exchange (ETDEWEB)

    Rood, S.B.; Zanewich, K.; Stefura, C. [Lethbridge Univ., Lethbridge, AB (Canada). Dept. of Biological Sciences; Mahoney, J.M. [Alberta Environmental Protection, Lethbridge, AB (Canada)

    2000-06-01

    Cottonwoods have shown an adaptation to the riparian zone by coordinating root elongation to maintain contact with the water table, whose depth varies with the elevation of the adjacent river. The rate of water decline on growth allocation and concentrations of endogenous gibberellins (GAs) in black cottonwood saplings were studied at the University of Lethbridge, Alberta. Water declines were achieved by using rhizopods, and root elongation approximately doubled in response whereas leaf area was reduced. At some point, a greater water decline rate led to water stress resulting in reduced growth, increased leaf diffusive resistance, decreased water potential, and leaf senescence and abscission. After extraction of endogenous GAs, they were purified and analysed by gas chromatography-selected ion monitoring with internal ({sup 2}H{sub 2})GA standards. The results showed that GAs were higher in shoot tips and sequentially lower in basal stems, root tips, leaves and upper roots. Noticeable relationships did not appear between GA concentration and growth allocation across the water decline treatments. Only GA{sub 8} showed a consistent reduction in plants experiencing water table decline. This research did not permit the authors to conclude whether endogenous GAs play a primary role in the regulation of root elongation in response to water table decline. 7 figs., 25 refs.

  4. Effect of water table fluctuations on phreatophytic root distribution.

    Science.gov (United States)

    Tron, Stefania; Laio, Francesco; Ridolfi, Luca

    2014-11-07

    The vertical root distribution of riparian vegetation plays a relevant role in soil water balance, in the partition of water fluxes into evaporation and transpiration, in the biogeochemistry of hyporheic corridors, in river morphodynamics evolution, and in bioengineering applications. The aim of this work is to assess the effect of the stochastic variability of the river level on the root distribution of phreatophytic plants. A function describing the vertical root profile has been analytically obtained by coupling a white shot noise representation of the river level variability to a description of the dynamics of root growth and decay. The root profile depends on easily determined parameters, linked to stream dynamics, vegetation and soil characteristics. The riparian vegetation of a river characterized by a high variability turns out to have a rooting system spread over larger depths, but with shallower mean root depths. In contrast, a lower river variability determines root profiles with higher mean root depths. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Standardization of sequential separation of naturally occurring radionuclides in drinking water

    International Nuclear Information System (INIS)

    Nair, Madhu G.; Rao, D.D.; Sathyapriya, R.S.; Sarkar, P.K.

    2012-01-01

    Human are constantly exposed to radiation originating from natural or manmade sources. The main contribution for internal dose is due to radionuclides from uranium and thorium series in drinking water. The distribution of these elements varies depending on the geological and physiological characteristics of the aquifer. With increased concern for radiological safety of public, it is necessary to evaluate the naturally occurring radionuclides in the drinking water

  6. Measurement of the 226Ra-concentration in bottled Austrian mineral waters and table beverages

    International Nuclear Information System (INIS)

    Friedmann, H.; Hernegger, F.

    1978-01-01

    226 Ra being regarded nowadays as a toxic trace element, a systementic examination of bottled Austrian mineral waters and table beverages has been carried out. Only in one case was the maximum allowable concentration of 3.3 pCi/l, a value set up by the WHO, clearly exceeded. (orig.) [de

  7. Accuracy of spatio-temporal RARX model predictions of water table depths

    NARCIS (Netherlands)

    Knotters, M.; Bierkens, M.F.P.

    2002-01-01

    Time series of water table depths (Ht) are predicted in space using a regionalised autoregressive exogenous variable (RARX) model with precipitation surplus (Pt) as input variable. Because of their physical basis, RARX model parameters can be guessed from auxiliary information such as a digital

  8. Response of anaerobic carbon cycling to water table manipulation in an Alaskan rich fen

    Science.gov (United States)

    Kane, E.S.; Chivers, M.R.; Turetsky, M.R.; Treat, C.C.; Petersen, D.G.; Waldrop, M.; Harden, J.W.; McGuire, A.D.

    2013-01-01

    To test the effects of altered hydrology on organic soil decomposition, we investigated CO2 and CH4 production potential of rich-fen peat (mean surface pH = 6.3) collected from a field water table manipulation experiment including control, raised and lowered water table treatments. Mean anaerobic CO2 production potential at 10 cm depth (14.1 ± 0.9 μmol C g−1 d−1) was as high as aerobic CO2 production potential (10.6 ± 1.5 μmol C g−1 d−1), while CH4 production was low (mean of 7.8 ± 1.5 nmol C g−1 d−1). Denitrification enzyme activity indicated a very high denitrification potential (197 ± 23 μg N g−1 d−1), but net NO-3 reduction suggested this was a relatively minor pathway for anaerobic CO2 production. Abundances of denitrifier genes (nirK and nosZ) did not change across water table treatments. SO2-4 reduction also did not appear to be an important pathway for anaerobic CO2 production. The net accumulation of acetate and formate as decomposition end products in the raised water table treatment suggested that fermentation was a significant pathway for carbon mineralization, even in the presence of NO-3. Dissolved organic carbon (DOC) concentrations were the strongest predictors of potential anaerobic and aerobic CO2 production. Across all water table treatments, the CO2:CH4 ratio increased with initial DOC leachate concentrations. While the field water table treatment did not have a significant effect on mean CO2 or CH4 production potential, the CO2:CH4 ratio was highest in shallow peat incubations from the drained treatment. These data suggest that with continued drying or with a more variable water table, anaerobic CO2 production may be favored over CH4 production in this rich fen. Future research examining the potential for dissolved organic substances to facilitate anaerobic respiration, or alternative redox processes that limit the effectiveness of organic acids as substrates in anaerobic metabolism, would help explain additional

  9. Simulation of the water-table altitude in the Biscayne Aquifer, southern Dade County, Florida, water years 1945-89

    Science.gov (United States)

    Merritt, M.L.

    1995-01-01

    A digital model of the flow system in the highly permeable surficial aquifer of southern Dade County, Florida, was constructed for the purposes of better understanding processes that influence the flow system and of supporting the construction of a subregional model of the transport of brackish water from a flowing artesian well. Problems that needed resolution in this endeavor included the development of methods to represent the influence of flowing surface water in seasonally inundated wetlands and the influence of a network of controlled canals developed in stages during the simulation time period (water years 1945-89). An additional problem was the general lack of natural aquifer boundaries near the boundaries of the study area. The model construction was based on a conceptual description of the Biscayne aquifer developed from the results of previous U.S. Geological Survey investigations. Modifications were made to an existing three- dimensional finite-difference simulator of ground- water flow to enable an upper layer of the grid to represent seasonally occurring overland sheetflow in a series of transient simulations of water levels from 1945 to 1989. A rewetting procedure was developed for the simulator that permitted resaturation of cells in this layer when the wet season recurred. An "equivalent hydraulic conductivity" coefficient was assigned to the overland flow layer that was analogous, subject to various approximations, to the use of the Manning equation. The surficial semiconfining peat and marl layers, levees, canals, and control structures were also represented as part of the model grid with the appropriate choices of hydraulic coefficient values. For most of the Biscayne aquifer grid cells, the value assigned to hydraulic conductivity for model calibration was 30,000 feet per day and the value assigned to porosity was 20 percent. Boundary conditions were specified near data sites having long-term records of surface-water stages or water-table

  10. Regional water table (2016) in the Mojave River and Morongo groundwater basins, southwestern Mojave Desert, California

    Science.gov (United States)

    Dick, Meghan; Kjos, Adam

    2017-12-07

    From January to April 2016, the U.S. Geological Survey (USGS), the Mojave Water Agency, and other local water districts made approximately 1,200 water-level measurements in about 645 wells located within 15 separate groundwater basins, collectively referred to as the Mojave River and Morongo groundwater basins. These data document recent conditions and, when compared with older data, changes in groundwater levels. A water-level contour map was drawn using data measured in 2016 that shows the elevation of the water table and general direction of groundwater movement for most of the groundwater basins. Historical water-level data stored in the USGS National Water Information System (https://waterdata.usgs.gov/nwis/) database were used in conjunction with data collected for this study to construct 37 hydrographs to show long-term (1930–2016) and short-term (1990–2016) water-level changes in the study area.

  11. Risk evaluation of ground water table decline as a type of desertification. A case study are: Southern Iran

    Energy Technology Data Exchange (ETDEWEB)

    Asrari, E.; Masoudi, M.

    2009-07-01

    This paper presents a model to assess risk of ground water table decline. Taking into consideration eleven indicators of lowering of ground water table the model identifies areas with Potential Risk (risky zones) and areas of Actual risk as well as projects the probability of the worse degradation in future. (Author) 7 refs.

  12. Risk evaluation of ground water table decline as a type of desertification. A case study are: Southern Iran

    International Nuclear Information System (INIS)

    Asrari, E.; Masoudi, M.

    2009-01-01

    This paper presents a model to assess risk of ground water table decline. Taking into consideration eleven indicators of lowering of ground water table the model identifies areas with Potential Risk (risky zones) and areas of Actual risk as well as projects the probability of the worse degradation in future. (Author) 7 refs.

  13. Sensitivity of stream flow and water table depth to potential climatic variability in a coastal forested watershed

    Science.gov (United States)

    Zhaohua Dai; Carl Trettin; Changsheng Li; Devendra M. Amatya; Ge Sun; Harbin Li

    2010-01-01

    A physically based distributed hydrological model, MIKE SHE, was used to evaluate the effects of altered temperature and precipitation regimes on the streamflow and water table in a forested watershed on the southeastern Atlantic coastal plain. The model calibration and validation against both streamflow and water table depth showed that the MIKE SHE was applicable for...

  14. Controlled laboratory experiments and modeling of vegetative filter strips with shallow water tables

    Science.gov (United States)

    Fox, Garey A.; Muñoz-Carpena, Rafael; Purvis, Rebecca A.

    2018-01-01

    Natural or planted vegetation at the edge of fields or adjacent to streams, also known as vegetative filter strips (VFS), are commonly used as an environmental mitigation practice for runoff pollution and agrochemical spray drift. The VFS position in lowlands near water bodies often implies the presence of a seasonal shallow water table (WT). In spite of its potential importance, there is limited experimental work that systematically studies the effect of shallow WTs on VFS efficacy. Previous research recently coupled a new physically based algorithm describing infiltration into soils bounded by a water table into the VFS numerical overland flow and transport model, VFSMOD, to simulate VFS dynamics under shallow WT conditions. In this study, we tested the performance of the model against laboratory mesoscale data under controlled conditions. A laboratory soil box (1.0 m wide, 2.0 m long, and 0.7 m deep) was used to simulate a VFS and quantify the influence of shallow WTs on runoff. Experiments included planted Bermuda grass on repacked silt loam and sandy loam soils. A series of experiments were performed including a free drainage case (no WT) and a static shallow water table (0.3-0.4 m below ground surface). For each soil type, this research first calibrated VFSMOD to the observed outflow hydrograph for the free drainage experiments to parameterize the soil hydraulic and vegetation parameters, and then evaluated the model based on outflow hydrographs for the shallow WT experiments. This research used several statistical metrics and a new approach based on hypothesis testing of the Nash-Sutcliffe model efficiency coefficient (NSE) to evaluate model performance. The new VFSMOD routines successfully simulated the outflow hydrographs under both free drainage and shallow WT conditions. Statistical metrics considered the model performance valid with greater than 99.5% probability across all scenarios. This research also simulated the shallow water table experiments with

  15. Simulation of upward flux from shallow water-table using UPFLOW model

    Directory of Open Access Journals (Sweden)

    M. H. Ali

    2013-11-01

    Full Text Available The upward movement of water by capillary rise from shallow water-table to the root zone is an important incoming flux. For determining exact amount of irrigation requirement, estimation of capillary flux or upward flux is essential. Simulation model can provide a reliable estimate of upward flux under variable soil and climatic conditions. In this study, the performance of model UPFLOW to estimate upward flux was evaluated. Evaluation of model performance was performed with both graphical display and statistical criteria. In distribution of simulated capillary rise values against observed field data, maximum data points lie around the 1:1 line, which means that the model output is reliable and reasonable. The coefficient of determination between observed and simulated values was 0.806 (r = 0.93, which indicates a good inter-relation between observed and simulated values. The relative error, model efficiency, and index of agreement were found as 27.91%, 85.93% and 0.96, respectively. Considering the graphical display of observed and simulated upward flux and statistical indicators, it can be concluded that the overall performance of the UPFLOW model in simulating actual upward flux from a crop field under variable water-table condition is satisfactory. Thus, the model can be used to estimate capillary rise from shallow water-table for proper estimation of irrigation requirement, which would save valuable water from over-irrigation.

  16. Significant skin burns may occur with the use of a water balloon in HIFU treatment

    Science.gov (United States)

    Ritchie, Robert; Collin, Jamie; Wu, Feng; Coussios, Constantin; Leslie, Tom; Cranston, David

    2012-10-01

    HIFU is a minimally-invasive therapy suitable for treating selected intra-abdominal tumors. Treatment is safe although skin burns may occur due to pre-focal heating. HIFU treatment of a renal transplant tumor located in the left lower abdomen was undertaken in our centre. Treatment was performed prone, requiring displacement of the abdominal wall away from the treatment field using a water balloon, constructed of natural rubber latex and filled with degassed water. Intra-operatively, ultrasound imaging and physical examination of the skin directly over the focal region was normal. Immediately post-operative, a full-thickness skin burn was evident at the periphery of the balloon location, outside the expected HIFU path. Three possibilities may account for this complication. Firstly, the water balloon may have acted as a lens, focusing the HIFU to a neo-focus off axis. Secondly, air bubbles may have been entrapped between the balloon and the skin, causing heating at the interface. Finally, heating of the isolated water within the balloon may have been sufficient to cause burning. In this case, the placement of a water balloon caused a significant skin burn. Care should be taken in their use as burns, situated off axis, may occur even if the overlying skin appears normal.

  17. Increasing the utility of regional water table maps: a new method for estimating groundwater recharge

    Science.gov (United States)

    Gilmore, T. E.; Zlotnik, V. A.; Johnson, M.

    2017-12-01

    Groundwater table elevations are one of the most fundamental measurements used to characterize unconfined aquifers, groundwater flow patterns, and aquifer sustainability over time. In this study, we developed an analytical model that relies on analysis of groundwater elevation contour (equipotential) shape, aquifer transmissivity, and streambed gradient between two parallel, perennial streams. Using two existing regional water table maps, created at different times using different methods, our analysis of groundwater elevation contours, transmissivity and streambed gradient produced groundwater recharge rates (42-218 mm yr-1) that were consistent with previous independent recharge estimates from different methods. The three regions we investigated overly the High Plains Aquifer in Nebraska and included some areas where groundwater is used for irrigation. The three regions ranged from 1,500 to 3,300 km2, with either Sand Hills surficial geology, or Sand Hills transitioning to loess. Based on our results, the approach may be used to increase the value of existing water table maps, and may be useful as a diagnostic tool to evaluate the quality of groundwater table maps, identify areas in need of detailed aquifer characterization and expansion of groundwater monitoring networks, and/or as a first approximation before investing in more complex approaches to groundwater recharge estimation.

  18. Impacts of soil conditioners and water table management on phosphorus loss in tile drainage from a clay loam soil.

    Science.gov (United States)

    Zhang, T Q; Tan, C S; Zheng, Z M; Welacky, T W; Reynolds, W D

    2015-03-01

    Adoption of waste-derived soil conditioners and refined water management can improve soil physical quality and crop productivity of fine-textured soils. However, the impacts of these practices on water quality must be assessed to ensure environmental sustainability. We conducted a study to determine phosphorus (P) loss in tile drainage as affected by two types of soil conditioners (yard waste compost and swine manure compost) and water table management (free drainage and controlled drainage with subirrigation) in a clay loam soil under corn-soybean rotation in a 4-yr period from 1999 to 2003. Tile drainage flows were monitored and sampled on a year-round continuous basis using on-site auto-sampling systems. Water samples were analyzed for dissolved reactive P (DRP), particulate P (PP), and total P (TP). Substantially greater concentrations and losses of DRP, PP, and TP occurred with swine manure compost than with control and yard waste compost regardless of water table management. Compared with free drainage, controlled drainage with subirrigation was an effective way to reduce annual and cumulative losses of DRP, PP, and TP in tile drainage through reductions in flow volume and P concentration with control and yard waste compost but not with swine manure compost. Both DRP and TP concentrations in tile drainage were well above the water quality guideline for P, affirming that subsurface loss of P from fine-textured soils can be one critical source for freshwater eutrophication. Swine manure compost applied as a soil conditioner must be optimized by taking water quality impacts into consideration. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  19. Naturally occurring radioactive elements, arsenic and other metals in drinking water from private wells

    International Nuclear Information System (INIS)

    Ek, Britt-Marie; Thunholm, Bo; Oestergren, Inger; Falk, Rolf; Mjoenes, Lars

    2008-04-01

    Approximately 50 % of all drinking water is extracted from groundwater. For private supply of drinking water almost 100 % emanates from groundwater. For approximately 1.2 of the 9 million Swedish citizens, private wells are the primary water source where 700 000 get their water from wells drilled in the bedrock. Radioactive elements and metals that occur naturally in the bedrock can be found in the well water. The radioactive elements include radon-222 ( 222 Rn), uranium (U), radium-226 ( 226 Ra) as well as polonium-210 ( 210 Po) and lead-210 ( 210 Pb), which are long-lived progeny of radon. In 2001 SGU and SSI initiated a collaboration to investigate the occurrence of radioactive elements and metals in water from private wells. Data sampling and analysis was completed in 2006. The aim of the project was to map the occurrence of radioactive elements in drinking water from private wells and to estimate their respective dose contribution. Another aim was to map metals and other elements in the water, to study temporal variations and possible co-variations between analysed elements. Sampling was conducted in a random fashion throughout the country. However, in regions where bedrock and soils are known to show enhanced concentrations of radioactive elements and arsenic the sampling density was increased. The analyses comprises: total beta activity, total alpha activity, radium-226, radon-222, uranium, aluminium, chloride, calcium, vanadium, chromium, iron, manganese, cobalt, nickel, copper, zink, arsenic, strontium, molybdenum, cadmium, barium, lead, thorium, boron, sodium, manganese, potassium, silica, alkalinity, sulfate, fluoride, phosphate, nitrate, pH and electric conductivity. In a few cases chemistry analyses of polonium-210 and lead-210 have been done. It was observed that the south-western part of Sweden, with exception for granite areas in the county of Bohuslaen, has relatively low concentrations of natural radioactive elements in the drinking water. The

  20. Verification of mid-ocean ballast water exchange using naturally occurring coastal tracers

    International Nuclear Information System (INIS)

    Murphy, Kathleen; Boehme, Jennifer; Coble, Paula; Cullen, Jay; Field, Paul; Moore, Willard; Perry, Elgin; Sherrell, Robert; Ruiz, Gregory

    2004-01-01

    We examined methods for verifying whether or not ships have performed mid-ocean ballast water exchange (BWE) on four commercial vessels operating in the Pacific and Atlantic Oceans. During BWE, a ship replaces the coastal water in its ballast tanks with water drawn from the open ocean, which is considered to harbor fewer organisms capable of establishing in coastal environments. We measured concentrations of several naturally occurring chemical tracers (salinity, six trace elements, colored dissolved organic matter fluorescence and radium isotopes) along ocean transects and in ballast tanks subjected to varying degrees of BWE (0-99%). Many coastal tracers showed significant concentration changes due to BWE, and our ability to detect differences between exchanged and unexchanged ballast tanks was greatest under multivariate analysis. An expanded dataset, which includes additional geographic regions, is now needed to test the generality of our results

  1. Verification of mid-ocean ballast water exchange using naturally occurring coastal tracers

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Kathleen; Boehme, Jennifer; Coble, Paula; Cullen, Jay; Field, Paul; Moore, Willard; Perry, Elgin; Sherrell, Robert; Ruiz, Gregory

    2004-04-01

    We examined methods for verifying whether or not ships have performed mid-ocean ballast water exchange (BWE) on four commercial vessels operating in the Pacific and Atlantic Oceans. During BWE, a ship replaces the coastal water in its ballast tanks with water drawn from the open ocean, which is considered to harbor fewer organisms capable of establishing in coastal environments. We measured concentrations of several naturally occurring chemical tracers (salinity, six trace elements, colored dissolved organic matter fluorescence and radium isotopes) along ocean transects and in ballast tanks subjected to varying degrees of BWE (0-99%). Many coastal tracers showed significant concentration changes due to BWE, and our ability to detect differences between exchanged and unexchanged ballast tanks was greatest under multivariate analysis. An expanded dataset, which includes additional geographic regions, is now needed to test the generality of our results.

  2. Water loss in table grapes: model development and validation under dynamic storage conditions

    Directory of Open Access Journals (Sweden)

    Ericsem PEREIRA

    2017-09-01

    Full Text Available Abstract Water loss is a critical problem affecting the quality of table grapes. Temperature and relative humidity (RH are essential in this process. Although mathematical modelling can be applied to measure constant temperature and RH impacts, it is proved that variations in storage conditions are normally encountered in the cold chain. This study proposed a methodology to develop a weight loss model for table grapes and validate its predictions in non-constant conditions of a domestic refrigerator. Grapes were maintained under controlled conditions and the weight loss was measured to calibrate the model. The model described the water loss process adequately and the validation tests confirmed its predictive ability. Delayed cooling tests showed that estimated transpiration rates in subsequent continuous temperature treatment was not significantly influenced by prior exposure conditions, suggesting that this model may be useful to estimate the weight loss consequences of interruptions in the cold chain.

  3. Developing a Long Short-Term Memory (LSTM) based model for predicting water table depth in agricultural areas

    Science.gov (United States)

    Zhang, Jianfeng; Zhu, Yan; Zhang, Xiaoping; Ye, Ming; Yang, Jinzhong

    2018-06-01

    Predicting water table depth over the long-term in agricultural areas presents great challenges because these areas have complex and heterogeneous hydrogeological characteristics, boundary conditions, and human activities; also, nonlinear interactions occur among these factors. Therefore, a new time series model based on Long Short-Term Memory (LSTM), was developed in this study as an alternative to computationally expensive physical models. The proposed model is composed of an LSTM layer with another fully connected layer on top of it, with a dropout method applied in the first LSTM layer. In this study, the proposed model was applied and evaluated in five sub-areas of Hetao Irrigation District in arid northwestern China using data of 14 years (2000-2013). The proposed model uses monthly water diversion, evaporation, precipitation, temperature, and time as input data to predict water table depth. A simple but effective standardization method was employed to pre-process data to ensure data on the same scale. 14 years of data are separated into two sets: training set (2000-2011) and validation set (2012-2013) in the experiment. As expected, the proposed model achieves higher R2 scores (0.789-0.952) in water table depth prediction, when compared with the results of traditional feed-forward neural network (FFNN), which only reaches relatively low R2 scores (0.004-0.495), proving that the proposed model can preserve and learn previous information well. Furthermore, the validity of the dropout method and the proposed model's architecture are discussed. Through experimentation, the results show that the dropout method can prevent overfitting significantly. In addition, comparisons between the R2 scores of the proposed model and Double-LSTM model (R2 scores range from 0.170 to 0.864), further prove that the proposed model's architecture is reasonable and can contribute to a strong learning ability on time series data. Thus, one can conclude that the proposed model can

  4. Simulating streamflow and water table depth with a coupled hydrological model

    Directory of Open Access Journals (Sweden)

    Alphonce Chenjerayi Guzha

    2010-09-01

    Full Text Available A coupled model integrating MODFLOW and TOPNET with the models interacting through the exchange of recharge and baseflow and river-aquifer interactions was developed and applied to the Big Darby Watershed in Ohio, USA. Calibration and validation results show that there is generally good agreement between measured streamflow and simulated results from the coupled model. At two gauging stations, average goodness of fit (R2, percent bias (PB, and Nash Sutcliffe efficiency (ENS values of 0.83, 11.15%, and 0.83, respectively, were obtained for simulation of streamflow during calibration, and values of 0.84, 8.75%, and 0.85, respectively, were obtained for validation. The simulated water table depths yielded average R2 values of 0.77 and 0.76 for calibration and validation, respectively. The good match between measured and simulated streamflows and water table depths demonstrates that the model is capable of adequately simulating streamflows and water table depths in the watershed and also capturing the influence of spatial and temporal variation in recharge.

  5. Perceived risks of produced water management and naturally occurring radioactive material content in North Dakota.

    Science.gov (United States)

    Torres, Luisa; Yadav, Om Prakash; Khan, Eakalak

    2017-07-01

    Unconventional oil and gas development using hydraulic fracturing has caused conflict and controversy across the globe including the U.S. where some States banned the practice. Nevertheless, North Dakota (ND) has supported the practice because the State perceives the risks to be acceptable and because it has brought growth and opportunities to small communities. However, social acceptance of new technology is based on a number of factors and not contingent on economic benefits. To date, no research has been conducted to understand public risk perception of hazards associated with produced water from hydraulic fracturing in ND. This study focuses on understanding the risk perception of select ND stakeholder groups regarding produced water management and naturally occurring radioactive material. The software Qualtrics was used to create an online survey, collect data, and perform statistical analysis. The most important variables that seem to influence risk perception are the images and thoughts associated with produced water, level of knowledge about produced water handling and content, and knowing how to proceed in case of a spill of produced water. Overall, social risk perception could be in alignment with actual technical risk if availability of objective information is improved. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Determination of natural occurring radionuclide and heavy metals in drinking water in Malaysia

    International Nuclear Information System (INIS)

    Nur Suraya Ahmad

    2012-01-01

    The objective of this study is to ascertain the activity concentration of naturally occurring radionuclide and selected heavy metals selected mineral and drinking waters sample in Malaysia. The activity concentration of natural radionuclide (mBq/ L) was determined by Gamma Spectroscopy Systems while the concentration of heavy metal (mg/ L) was determined by the Induces Couple Plasma Mass Spectrometry (ICP-MS). The mineral and drinking water samples used in this study were Segar UKM, Giant, Ice Mountain (600 ml), Ice Mountain (1600 ml), Spritzer, Reverse Osmosis, and fresh tap water. The results of the study found 3 natural occurring radioactive materials (NORM) found for example - U-238, Ra-226 and Ra-228. The activity concentration determined was 0.00 mBq/ L to 1.71 mBq/ L for U-238, 0.00 - 32.46 mBq/ L for Ra-226 and 0.00 - 12.01 mBq/ L for Ra-228 respectively. The concentration of heavy metals Zn, Fe, As, Cl, Mn, Cu and Pb determined in this study were in the range of 0.000 - 0.003 mg/ L, 0.002-0.018 mg/ L, 0.000 - 0.007 mg/ L, 6.152 - 57.724 mg/ L, 0.000 - 0.016 μg/ L, 0.058 - 0.766 μg/ L and 0.000 - 0.380 μg/ L respectively. In general, the result of this study indicate that the activity concentration NORM and selected heavy metals in the studied mineral and drinking water samples were low and not exceed the limit set by World Organization (WHO) and Malaysian Food Regulations 1985. Thus, all the studied water samples complying the Malaysian drinking standard and safe to be consumed. (author)

  7. "Periodic-table-style" paper device for monitoring heavy metals in water.

    Science.gov (United States)

    Li, Miaosi; Cao, Rong; Nilghaz, Azadeh; Guan, Liyun; Zhang, Xiwang; Shen, Wei

    2015-03-03

    If a paper-based analytical device (μ-PAD) could be made by printing indicators for detection of heavy metals in chemical symbols of the metals in a style of the periodic table of elements, it could be possible for such μ-PAD to report the presence and the safety level of heavy metal ions in water simultaneously and by text message. This device would be able to provide easy solutions to field-based monitoring of heavy metals in industrial wastewater discharges and in irrigating and drinking water. Text-reporting could promptly inform even nonprofessional users of the water quality. This work presents a proof of concept study of this idea. Cu(II), Ni(II), and Cr(VI) were chosen to demonstrate the feasibility, specificity, and reliability of paper-based text-reporting devices for monitoring heavy metals in water.

  8. Travel Times of Water Derived from Three Naturally Occurring Cosmogenic Radioactive Isotopes

    Science.gov (United States)

    Visser, Ate; Thaw, Melissa; Deinhart, Amanda; Bibby, Richard; Esser, Brad

    2017-04-01

    confirm a small fraction of younger (travel time responses to hydrological conditions and further characterize the catchment properties. Combined analysis of three cosmogenic tracers provides a unique insight into the functioning of the catchment and constrains the volume of subsurface water storage. Short-lived naturally occurring radioactive isotopes sulfur-35 and sodium-22 are especially useful for vulnerability assessment of springs and karst systems where a contribution of very young water is expected. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-717377

  9. Effects of Permanently Raised Water Tables on Forest Overstory Vegetation in the Vicinity of the Tennessee-Tombigbee Waterway.

    Science.gov (United States)

    1982-08-01

    Mississippi Valley* Common Name Scientific Name Very Tolerant** Water hickory Carya aquatica Pecan C. illinoensis Buttonbush Cephalanthus occidentalis...Table I (Concluded) Common Name Scientific Name Intolerant* Ironwood Carpinus caroliniana Bitternut hickory Carya cordiformis Shellbark

  10. High-Resolution Assimilation of GRACE Terrestrial Water Storage Observations to Represent Local-Scale Water Table Depths

    Science.gov (United States)

    Stampoulis, D.; Reager, J. T., II; David, C. H.; Famiglietti, J. S.; Andreadis, K.

    2017-12-01

    Despite the numerous advances in hydrologic modeling and improvements in Land Surface Models, an accurate representation of the water table depth (WTD) still does not exist. Data assimilation of observations of the joint NASA and DLR mission, Gravity Recovery and Climate Experiment (GRACE) leads to statistically significant improvements in the accuracy of hydrologic models, ultimately resulting in more reliable estimates of water storage. However, the usually shallow groundwater compartment of the models presents a problem with GRACE assimilation techniques, as these satellite observations account for much deeper aquifers. To improve the accuracy of groundwater estimates and allow the representation of the WTD at fine spatial scales we implemented a novel approach that enables a large-scale data integration system to assimilate GRACE data. This was achieved by augmenting the Variable Infiltration Capacity (VIC) hydrologic model, which is the core component of the Regional Hydrologic Extremes Assessment System (RHEAS), a high-resolution modeling framework developed at the Jet Propulsion Laboratory (JPL) for hydrologic modeling and data assimilation. The model has insufficient subsurface characterization and therefore, to reproduce groundwater variability not only in shallow depths but also in deep aquifers, as well as to allow GRACE assimilation, a fourth soil layer of varying depth ( 1000 meters) was added in VIC as the bottom layer. To initialize a water table in the model we used gridded global WTD data at 1 km resolution which were spatially aggregated to match the model's resolution. Simulations were then performed to test the augmented model's ability to capture seasonal and inter-annual trends of groundwater. The 4-layer version of VIC was run with and without assimilating GRACE Total Water Storage anomalies (TWSA) over the Central Valley in California. This is the first-ever assimilation of GRACE TWSA for the determination of realistic water table depths, at

  11. The role of naturally occurring biofilm in the treatment of mine water in abandoned uranium mine

    International Nuclear Information System (INIS)

    Mielnicki, S.; Sklodowska, A.; Michalska, B.

    2014-01-01

    The uranium mine in Kowary (SW Poland) was active from 1948 to 1967. After exploitation ceased the mine was abandoned and from the beginning of 21"s"t century it is a touristic attraction of this region of Poland. The largest uranium mining fields, Kowary and Kowary-Podgorze, were located in southern part of the metamorphic cover of the Karkonosze Granite. In the mine dumps at Kowary- Podgorze ore fragments containing up to 0.15% of uranium can still be found. Several dumps have been left in the Kowary Podgorze vicinity as the post mining uranium waste. The dump of adits Nos. 19 and 19a at Kowary Podgorze is located in the Jedlica River valley. Water from adit No. 19a is still discharged by the pipe directly to the Jedlica River. In the end of this pipe a small dam was built to regulate the level of water in adit and small reservoir of mine water was created in this place. The level of uranium observed in water before dam is between 10 μg/dm"3 and 670 μg/dm"3. The bottom of reservoir is covered by strongly mineralized biofilm containing up to 60 mg U/kg (dry weight), 1 500 mg As/kg, 10 000 mg Al/kg and about 1700 mg Mn/kg. Water in Jedlica River contains 6- 7 μg U/dm"3, 16 μg As/dm"3 and about 10 μg Mn/dm"3 and these values are within the limits for non contaminated surface water. The water from the reservoir together with the biofilm is discharged minimum twice a year immediately to Jedlica River causing a temporary increase of contaminants (beyond the limits) and dispersion of uranium and arsenic up to 20 km from the main source of pollution. It seems that biofilm from reservoir acts as an active filter that removes main contaminants from mine water mainly through biosorption. Laboratory studies show that sorption complexes are relatively stable. Maximum 10% of absorbed uranium was eluted by EDTA buffer or acetic acid (soluble and carbonate fraction). Arsenic was eluted in 25% by phosphate buffer (ion exchange) and almost all iron and cadmium (occurring in

  12. Environmental impact assessment of quarries under water table: state of the art

    International Nuclear Information System (INIS)

    Menatti, M.; Vismara, R.

    2009-01-01

    After an overview of environmental problems concerning pits under water table, data and results showed in a few examples of literature and in some Environmental Impact Study are summarized. A close examination about sector normative instruments, in the field of E.I.A. (Environmental Impact Assessment) and S.E.A. (Strategic Environmental Assessment) is showed, through some key elements obtained from a few guidelines expressed by control and authorization governmental authority.In addition, the paper deals with a specific problem about wash water management and, in particular, silt material management; the possible impacts derived from the directly wash water introduction in the pit lake and from the use of settling lagoon are analyzed. [it

  13. Measuring the Change in Water Table with Gravity Methods - a Controlled Experiment

    DEFF Research Database (Denmark)

    Lund, S; Christiansen, Lars; Andersen, O. B.

    2009-01-01

    Gravity changes linearly with the change in soil water content. With the GRACE satellite mission the interest for ground-based gravity methods in hydrology has gained new attention. Time-lapse gravity data have the potential to constrain hydrological model parameters in a calibration scheme....... The greatest potential is seen for specific yield. The gravity signal from hydrology is small (10^-8 m/s^2 level) and the application of ground-based methods is mainly limited by the sensitivity of available instruments. In order to demonstrate the ability of the Scintrex CG-5 gravity meter to detect a change...... in water content, a controlled experiment was set up in 30 m by 20 m basin. The water table was lowered 0.69 m within 1½ hours and the corresponding gravity signal measured using two different approaches: a time series measurements at one location and a gravity network measurement including four points...

  14. A study on the influence of tides on the water table conditions of the shallow coastal aquifers

    Science.gov (United States)

    Singaraja, C.; Chidambaram, S.; Jacob, Noble

    2018-03-01

    Tidal variation and water level in aquifer is an important function in the coastal environment, this study attempts to find the relationship between water table fluctuation and tides in the shallow coastal aquifers. The study was conducted by selecting three coastal sites and by monitoring the water level for every 2-h interval in 24 h of observation. The study was done during two periods of full moon and new moon along the Cuddalore coastal region of southern part of Tamil Nadu, India. The study shows the relationship between tidal variation, water table fluctuations, dissolved oxygen, and electrical conductivity. An attempt has also been made in this study to approximate the rate of flow of water. Anyhow, the differences are site specific and the angle of inclination of the water table shows a significant relation to the mean sea level, with respect to the distance of the point of observation from the sea and elevation above mean sea level.

  15. Secondary mineral evidence of large-scale water table fluctuations at Yucca Mountain, Nye County, Nevada

    International Nuclear Information System (INIS)

    Whelan, J.F.; Moscati, R.J.; Marshall, B.D

    1997-12-01

    At Yucca Mountain, currently under consideration as a potential permanent underground repository for high-level radioactive wastes, the present-day water table is 500 to 700 m deep. This thick unsaturated zone (UZ) is part of the natural barrier system and is regarded as a positive attribute of the potential site. The USGS has studied the stable isotopes and petrography of secondary calcite and silica minerals that coat open spaces in the UZ and form irregular veins and masses in the saturated zone (SZ). This paper reviews the findings from the several studies undertaken at Yucca Mountain on its mineralogy

  16. Experimental study of the hydrodynamic instabilities occurring in boiling-water reactors

    International Nuclear Information System (INIS)

    Fabreca, S.

    1964-10-01

    The subjects is an experimental out-of pile loop study of the hydrodynamic oscillations occurring in boiling-water reactors. The study was carried out at atmospheric pressure and at pressure of about 8 atmospheres, in channels heated electrically by a constant and uniform specified current. In the test at 8 atmospheres the channel was a round tube of approximately 6 mm interior diameter. At 1 atmosphere a ring-section channel was used, 10 * 20 mm in diameter, with an inner heating tube and an outer tube of pyrex. It was possible to operate with natural convection and also with forced convection with test-channel by-pass. The study consists of 3 parts: 1. Preliminary determination of the laws governing pressure-drop during boiling. 2. Determination of the fronts at which oscillation appears, within a wide range of the parameters involved. 3. A descriptive study of the oscillations and measurement of the periods. The report gives the oscillation fronts with natural and forced convection for various values of the singular pressure drop at the channel inlet and for various riser lengths. The results are presented in non-dimensional form, which is available, in first approximation, for all geometric scales and for all fluids. Besides the following points were observed: - the wall (nature and thickness) can be an important factor ; - oscillation can occur in a horizontal channel. (author) [fr

  17. Analysis of Tide and Offshore Storm-Induced Water Table Fluctuations for Structural Characterization of a Coastal Island Aquifer

    Science.gov (United States)

    Trglavcnik, Victoria; Morrow, Dean; Weber, Kela P.; Li, Ling; Robinson, Clare E.

    2018-04-01

    Analysis of water table fluctuations can provide important insight into the hydraulic properties and structure of a coastal aquifer system including the connectivity between the aquifer and ocean. This study presents an improved approach for characterizing a permeable heterogeneous coastal aquifer system through analysis of the propagation of the tidal signal, as well as offshore storm pulse signals through a coastal aquifer. Offshore storms produce high wave activity, but are not necessarily linked to significant onshore precipitation. In this study, we focused on offshore storm events during which no onshore precipitation occurred. Extensive groundwater level data collected on a sand barrier island (Sable Island, NS, Canada) show nonuniform discontinuous propagation of the tide and offshore storm pulse signals through the aquifer with isolated inland areas showing enhanced response to both oceanic forcing signals. Propagation analysis suggests that isolated inland water table fluctuations may be caused by localized leakage from a confined aquifer that is connected to the ocean offshore but within the wave setup zone. Two-dimensional groundwater flow simulations were conducted to test the leaky confined-unconfined aquifer conceptualization and to identify the effect of key parameters on tidal signal propagation in leaky confined-unconfined coastal aquifers. This study illustrates that analysis of offshore storm signal propagation, in addition to tidal signal propagation, provides a valuable and low resource approach for large-scale characterization of permeable heterogeneous coastal aquifers. Such an approach is needed for the effective management of coastal environments where water resources are threatened by human activities and the changing climate.

  18. Worldwide Open Proficiency Test: Determination of Naturally Occurring Radionuclides in Phosphogypsum and Water

    International Nuclear Information System (INIS)

    2010-01-01

    A reliable determination of naturally occurring radionuclides in phosphogypsum is necessary to comply with the radiation protection and environmental regulations. This proficiency test (PT) is one of the series of the world wide proficiency tests organised every year by the IAEA Terrestrial Environment Laboratory. This series of PTs is designed to identify analytical problems, to support Member State laboratories to maintain their accreditation and to provide a forum for discussions regarding the analysis of naturally occurring radionuclides. The range of sample types available for analysis has been mainly at environmental levels. In this PT, the test item set consisted of six samples: one phosphogypsum (the IAEA-434 reference material) and five water samples spiked with natural radionuclides. The main task of the participating laboratories was to identify and traceably quantify the activity levels of radionuclides present in these matrices. The tasks of the IAEA were to prepare and distribute the samples to the participating laboratories, to collect and interpret analysis results and to compile a comprehensive report. The certified massic activity values of all radionuclides used in this PT were traceable to international standards of radioactivity. In this PT, 1800 test items (reference materials) were prepared and distributed to 300 laboratories from 76 countries in November 2008. The deadline for receiving the results from the participants was set at 15 May 2009. The participating laboratories were requested to analyse Ra-226, U-234 and U-238 in water samples 01 and 02, and gross alpha/beta in water samples 03, 04 and 05. In the phosphogypsum sample number 06 the participants were asked to analyse Pb-210, Ra-226, Th-230, U-234 and U-238. The analytical results of the participating laboratories were compared with the reference values assigned to the reference materials, and a rating system was applied. Three National Metrology Institutes (NMI) and six expert

  19. Effectiveness of table top water pitcher filters to remove arsenic from drinking water.

    Science.gov (United States)

    Barnaby, Roxanna; Liefeld, Amanda; Jackson, Brian P; Hampton, Thomas H; Stanton, Bruce A

    2017-10-01

    Arsenic contamination of drinking water is a serious threat to the health of hundreds of millions of people worldwide. In the United States ~3 million individuals drink well water that contains arsenic levels above the Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 10μg/L. Several technologies are available to remove arsenic from well water including anion exchange, adsorptive media and reverse osmosis. In addition, bottled water is an alternative to drinking well water contaminated with arsenic. However, there are several drawbacks associated with these approaches including relatively high cost and, in the case of bottled water, the generation of plastic waste. In this study, we tested the ability of five tabletop water pitcher filters to remove arsenic from drinking water. We report that only one tabletop water pitcher filter tested, ZeroWater®, reduced the arsenic concentration, both As 3+ and As 5+ , from 1000μg/L to water and its use reduces plastic waste associated with bottled water. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Understanding and quantifying focused, indirect groundwater recharge from ephemeral streams using water table fluctuations

    Science.gov (United States)

    Cuthbert, M. O.; Acworth, R. I.; Andersen, M. S.; Larsen, J. R.; McCallum, A. M.; Rau, G. C.; Tellam, J. H.

    2016-02-01

    Understanding and managing groundwater resources in drylands is a challenging task, but one that is globally important. The dominant process for dryland groundwater recharge is thought to be as focused, indirect recharge from ephemeral stream losses. However, there is a global paucity of data for understanding and quantifying this process and transferable techniques for quantifying groundwater recharge in such contexts are lacking. Here we develop a generalized conceptual model for understanding water table and groundwater head fluctuations due to recharge from episodic events within ephemeral streams. By accounting for the recession characteristics of a groundwater hydrograph, we present a simple but powerful new water table fluctuation approach to quantify focused, indirect recharge over both long term and event time scales. The technique is demonstrated using a new, and globally unparalleled, set of groundwater observations from an ephemeral stream catchment located in NSW, Australia. We find that, following episodic streamflow events down a predominantly dry channel system, groundwater head fluctuations are controlled by pressure redistribution operating at three time scales from vertical flow (days to weeks), transverse flow perpendicular to the stream (weeks to months), and longitudinal flow parallel to the stream (years to decades). In relative terms, indirect recharge decreases almost linearly away from the mountain front, both in discrete monitored events as well as in the long-term average. In absolute terms, the estimated indirect recharge varies from 80 to 30 mm/a with the main uncertainty in these values stemming from uncertainty in the catchment-scale hydraulic properties.

  1. The effect of changing water table on methane fluxes at two Finnish mire sites

    International Nuclear Information System (INIS)

    Martikainen, P.J.; Nykaenen, H.; Crill, P.; Silvola, J.

    1992-01-01

    Methane fluxes were measured using static chamber technique on a minerotrophic fen and an ombrotrophic peat bog site located in the Lakkasuo mire complex in central Finland. Both sites consisted of a virgin area and an area drained in 1961 by ditching. The measurements in 1991 were made biweekly from spring thaw to winter freezing. During this period, the mean CH4 emission from the virgin minerotrophic site and virgin ombrotrophic site was 98 mg/m -2 d -1 and 40 mg/m -2 d -1 , respectively. The mean emission of CH 4 from the drained ombrotrophic site was 18 mg/m -2 d -1 . The drained minerotrophic site consumed methane during most of the measuring period, the average uptake was 0.13 mg/m2d. Draining had lowered the average water table by 4 cm at the ombrotrophic site and by 20 cm at minerotrophic site. The possible reasons for the different development of the water table and methane fluxes at ombrotrophic and minerotrophic sites after drainer are discussed

  2. Peatland pines as a proxy for water table fluctuations: disentangling tree growth, hydrology and possible human influence.

    Science.gov (United States)

    Smiljanić, Marko; Seo, Jeong-Wook; Läänelaid, Alar; van der Maaten-Theunissen, Marieke; Stajić, Branko; Wilmking, Martin

    2014-12-01

    Dendrochronological investigations of Scots pine (Pinus sylvestris L.) growing on Männikjärve peatland in central Estonia showed that annual tree growth of peatland pines can be used as a proxy for past variations of water table levels. Reconstruction of past water table levels can help us to better understand the dynamics of various ecological processes in peatlands, e.g. the formation of vegetation patterns or carbon and nitrogen cycling. Männikjärve bog has one of the longest water table records in the boreal zone, continuously monitored since 1956. Common uncertainties encountered while working with peatland trees (e.g. narrow, missing and wedging rings) were in our case exacerbated with difficulties related to the instability of the relationship between tree growth and peatland environment. We hypothesized that the instable relationship was mainly due to a significant change of the limiting factor, i.e. the rise of the water table level due to human activity. To test our hypothesis we had to use several novel methods of tree-ring chronology analysis as well as to test explicitly whether undetected missing rings biased our results. Since the hypothesis that the instable relationship between tree growth and environment was caused by a change in limiting factor could not be rejected, we proceeded to find possible significant changes of past water table levels using structural analysis of the tree-ring chronologies. Our main conclusions were that peatland pines can be proxies to water table levels and that there were several shifting periods of high and low water table levels in the past 200 years. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Effects of soil water table regime on tree community species richness and structure of alluvial forest fragments in Southeast Brazil.

    Science.gov (United States)

    Silva, A C; Higuchi, P; van den Berg, E

    2010-08-01

    In order to determine the influence of soil water table fluctuation on tree species richness and structure of alluvial forest fragments, 24 plots were allocated in a point bar forest and 30 plots in five forest fragments located in a floodplain, in the municipality of São Sebastião da Bela Vista, Southeast Brazil, totalizing 54, 10 X 20 m, plots. The information recorded in each plot were the soil water table level, diameter at breast height (dbh), total height and botanical identity off all trees with dbh > 5 cm. The water table fluctuation was assessed through 1 m deep observation wells in each plot. Correlations analysis indicated that sites with shallower water table in the flooding plains had a low number of tree species and high tree density. Although the water table in the point bar remained below the wells during the study period, low tree species richness was observed. There are other events taking place within the point bar forest that assume a high ecological importance, such as the intensive water velocity during flooding and sedimentation processes.

  4. Effects of soil water table regime on tree community species richness and structure of alluvial forest fragments in Southeast Brazil

    Directory of Open Access Journals (Sweden)

    AC. Silva

    Full Text Available In order to determine the influence of soil water table fluctuation on tree species richness and structure of alluvial forest fragments, 24 plots were allocated in a point bar forest and 30 plots in five forest fragments located in a floodplain, in the municipality of São Sebastião da Bela Vista, Southeast Brazil, totalizing 54, 10 X 20 m, plots. The information recorded in each plot were the soil water table level, diameter at breast height (dbh, total height and botanical identity off all trees with dbh > 5 cm. The water table fluctuation was assessed through 1 m deep observation wells in each plot. Correlations analysis indicated that sites with shallower water table in the flooding plains had a low number of tree species and high tree density. Although the water table in the point bar remained below the wells during the study period, low tree species richness was observed. There are other events taking place within the point bar forest that assume a high ecological importance, such as the intensive water velocity during flooding and sedimentation processes.

  5. Almera Proficiency Test Determination of Naturally Occurring Radionuclides in Phosphogypsum and Water

    International Nuclear Information System (INIS)

    2010-01-01

    Phosphogypsum is generated as a by-product of the phosphoric acid based fertilizer industry. The discharge of phosphogypsum on earth surface deposits is a potential source of enhanced natural radiation and heavy metals, and the resulting environmental impact should be considered carefully to ensure safety and compliance with environmental regulations. A reliable determination of technologically enhanced naturally occurring radioactive materials in phosphogypsum is necessary to comply with the radiation protection and environmental regulations. This proficiency test (PT) is one of the series of the ALMERA network proficiency tests organised on a regular basis by the Chemistry Unit of the IAEA Terrestrial Environment Laboratory. These proficiency tests are designed to identify analytical problems, to support Member States laboratories to maintain their preparedness and to provide rapid and reliable analytical results. In this PT, the test item set consisted of six samples: one phosphogypsum (the IAEA-434 reference material) and five water samples spiked with natural radionuclides. The main task of the participating laboratories was to identify and quantify the activity levels of radionuclides present in these matrices. The tasks of IAEA were to prepare and distribute the samples to the participating laboratories, to collect and interpret analysis results and to compile a comprehensive report. The certified massic activity values of all radionuclides used in this PT were fulfilling the requirements of metrological traceability to international standards of radioactivity. In this PT, 306 test items (reference materials) were prepared and distributed to 52 participants from 40 countries in November 2008. The deadline for receiving the results from the participants was set to15 May 2009. For gross alpha/beta results the deadline was one working day from the date of sample delivery. The participating laboratories were requested to analyse Ra-226, U-234 and U-238 in water

  6. Climate change and water table fluctuation: Implications for raised bog surface variability

    Science.gov (United States)

    Taminskas, Julius; Linkevičienė, Rita; Šimanauskienė, Rasa; Jukna, Laurynas; Kibirkštis, Gintautas; Tamkevičiūtė, Marija

    2018-03-01

    Cyclic peatland surface variability is influenced by hydrological conditions that highly depend on climate and/or anthropogenic activities. A low water level leads to a decrease of peatland surface and an increase of C emissions into the atmosphere, whereas a high water level leads to an increase of peatland surface and carbon sequestration in peatlands. The main aim of this article is to evaluate the influence of hydrometeorological conditions toward the peatland surface and its feedback toward the water regime. A regional survey of the raised bog water table fluctuation and surface variability was made in one of the largest peatlands in Lithuania. Two appropriate indicators for different peatland surface variability periods (increase and decrease) were detected. The first one is an 200 mm y- 1 average net rainfall over a three-year range. The second one is an average annual water depth of 25-30 cm. The application of these indicators enabled the reconstruction of Čepkeliai peatland surface variability during a 100 year period. Processes of peatland surface variability differ in time and in separate parts of peatland. Therefore, internal subbasins in peatland are formed. Subbasins involve autogenic processes that can later affect their internal hydrology, nutrient status, and vegetation succession. Internal hydrological conditions, surface fluctuation, and vegetation succession in peatland subbasins should be taken into account during evaluation of their state, nature management projects, and other peatland research works.

  7. Development of Historical Water Table Maps of the 200 West Area of the Hanford Site (1950-1970)

    International Nuclear Information System (INIS)

    Kinney, Teena M.; McDonald, John P.

    2006-01-01

    A series of detailed historical water-table maps for the 200-West Area of the Hanford Site was made to aid interpretation of contaminant distribution in the upper aquifer. The contaminants are the result of disposal of large volumes of waste to the ground during Hanford Site operations, which began in 1944 and continued into the mid-1990s. Examination of the contaminant plumes that currently exist on site shows that the groundwater beneath the 200-West Area has deviated from its pre-Hanford west-to-east flow direction during the past 50 years. By using historical water-level measurements from wells around the 200-West Area, it was possible to create water-table contour maps that show probable historic flow directions. These maps are more detailed than previously published water-table maps that encompass the entire Hanford Site.

  8. Shallow water table effects on water, sediment, and pesticide transport in vegetative filter strips - Part 1: nonuniform infiltration and soil water redistribution

    OpenAIRE

    Munoz Carpena, R.; Lauvernet, C.; Carluer, N.

    2018-01-01

    Vegetation buffers like vegetative filter strips (VFSs) are often used to protect water bodies from surface runoff pollution from disturbed areas. Their typical placement in floodplains often results in the presence of a seasonal shallow water table (WT) that can decrease soil infiltration and increase surface pollutant transport during a rainfall-runoff event. Simple and robust components of hydrological models are needed to analyze the impacts of WT in the landscape. To si...

  9. CORRELATION BETWEEN RAINFALL PATTERNS AND THE WATER TABLE IN THE GENERAL SEPARATIONS AREA OF THE SAVANNAH RIVER SITE

    International Nuclear Information System (INIS)

    Smith, C.

    2009-01-01

    The objective of the study was to evaluate rainfall and water table elevation data in search of a correlation that could be used to understand and predict water elevation changes. This information will be useful in placing screen zones for future monitoring wells and operations of groundwater treatment units. Fifteen wells in the General Separations Area (GSA) at Savannah River Site were evaluated from 1986 through 2001. The study revealed that the water table does respond to rainfall with minimal delay. (Water level information was available monthly, which restricted the ability to evaluate a shorter delay period.) Water elevations were found to be related to the cumulative sum (Q-Delta Sum) of the difference between the average rainfall for a specific month and the actual rainfall for that month, calculated from an arbitrary starting point. Water table elevations could also be correlated between wells, but using the right well for correlation was very important. The strongest correlation utilized a quadratic equation that takes into account the rainfall in a specific area and the rainfall from an adjacent area that contributes through a horizontal flow. Specific values vary from well to well as a result of geometry and underground variations. R2's for the best models ranged up to 0.96. The data in the report references only GSA wells but other wells (including confined water tables) on the site have been observed to return similar water level fluctuation patterns

  10. The impact of water table drawdown and drying on subterranean aquatic fauna in in-vitro experiments.

    Directory of Open Access Journals (Sweden)

    Christine Stumpp

    Full Text Available The abstraction of groundwater is a global phenomenon that directly threatens groundwater ecosystems. Despite the global significance of this issue, the impact of groundwater abstraction and the lowering of groundwater tables on biota is poorly known. The aim of this study is to determine the impacts of groundwater drawdown in unconfined aquifers on the distribution of fauna close to the water table, and the tolerance of groundwater fauna to sediment drying once water levels have declined. A series of column experiments were conducted to investigate the depth distribution of different stygofauna (Syncarida and Copepoda under saturated conditions and after fast and slow water table declines. Further, the survival of stygofauna under conditions of reduced sediment water content was tested. The distribution and response of stygofauna to water drawdown was taxon specific, but with the common response of some fauna being stranded by water level decline. So too, the survival of stygofauna under different levels of sediment saturation was variable. Syncarida were better able to tolerate drying conditions than the Copepoda, but mortality of all groups increased with decreasing sediment water content. The results of this work provide new understanding of the response of fauna to water table drawdown. Such improved understanding is necessary for sustainable use of groundwater, and allows for targeted strategies to better manage groundwater abstraction and maintain groundwater biodiversity.

  11. Precipitation patterns and moisture fluxes in a sandy, tropical environment with a shallow water table

    Science.gov (United States)

    Minihane, M. R.; Freyberg, D. L.

    2011-08-01

    Identifying the dominant mechanisms controlling recharge in shallow sandy soils in tropical climates has received relatively little attention. Given the expansion of coastal fill using marine sands and the growth of coastal populations throughout the tropics, there is a need to better understand the nature of water balances in these settings. We use time series of field observations at a coastal landfill in Singapore coupled with numerical modeling using the Richards' equation to examine the impact of precipitation patterns on soil moisture dynamics, including percolation past the root zone and recharge, in such an environment. A threshold in total precipitation event depth, much more so than peak precipitation intensity, is the strongest event control on recharge. However, shallow antecedent moisture, and therefore the timing between events along with the seasonal depth to water table, also play significant roles in determining recharge amounts. For example, at our field site, precipitation events of less than 3 mm per event yield little to no direct recharge, but for larger events, moisture content changes below the root zone are linearly correlated to the product of the average antecedent moisture content and the total event precipitation. Therefore, water resources planners need to consider identifying threshold precipitation volumes, along with the multiple time scales that capture variability in event antecedent conditions and storm frequency in assessing the role of recharge in coastal water balances in tropical settings.

  12. Haemozoin (B-haematin) biomineralization occurs by self-assembly near the lipid/water interface

    CSIR Research Space (South Africa)

    Egan, TJ

    2006-09-01

    Full Text Available remained unknown, although lipids or proteins have been suggested to catalyse its formation. We have found that B-haematin (synthetic haemozoin) forms rapidly under physiologically realistic conditions near octanol/water, pentanol/water and lipid...

  13. THE OCCURANCE OF ALUMINIUM IN MUNICIPAL TREATED WATER SUPPLY OF SOUTH EAST AREA OF IRAN

    OpenAIRE

    K.Imandel; D.D. Farhud; A.Derakhtian

    1994-01-01

    In recent years, a potential connection between human intake of aluminum and Alzheimer’s disease has drawn attention to the aluminum concentration in drinking water. It is therefore of interest to investigate the aluminum concentration m drinking water, produced under different circumstances. A random selection of 152 water samples were taken by the supply source including ground, surface and a combination of both for determination of aluminum concentration in the type of water (raw, finished...

  14. Application of naturally occurring isotopes and artificial radioactive tracer for monitoring water flooding in oil field

    International Nuclear Information System (INIS)

    Ahmad, M.; Khan, I.H.; Farooq, M.; Tasneem, M.A.; Rafiq, M.; Din, U.G.; Gul, S.

    2002-03-01

    Water flooding is an important operation to enhance oil recovery. Water is injected in the oil formation under high pressure through an injection well. Movement of the injected water is needed to be traced to test the performance of water flood, investigate unexpected anomalies in flow and verify suspected geological barriers or flow channels, etc. In the present study environmental isotopes and artificial radiotracer (tritium) were used at Fimkassar Oil Field of Oil and Gas Development Company Limited (OGDCL) where water flooding was started in March 1996 in Sakessar formation to maintain its pressure and enhance the oil recovery. Environmental isotopes: /sup 18/O, /sup 2/H and /sup 3/H, and chloride contents were used to determine the breakthrough/transit time and contribution of fresh injected water. Water samples were collected from the injection well, production well and some other fields for reference indices of Sakessar Formation during June 1998 to August 1999. These samples were analyzed for the /sup 18/O, /sup 2/H and /sup 3/H, and chloride contents. Results show that the water of production well is mixture of fresh water and formation water. The fresh water contribution varied from 67% to 80%, while remaining component was the old recharged formation water. This percentage did not change significantly from the time of break-through till the last sampling which indicates good mixing in the reservoir and absence of any quick channel. The initial breakthrough time was 27 months as the fresh water contributed significantly in the first appearance of water in the production well in June 1998. Tritium tracer, which was injected in November 1998, appeared in the production well after 8 months. It show that breakthrough time decreased with the passage of time. /sup 14/C of inorganic carbon in the water in Chorgali and Sakessar Formations was also analyzed which indicates that the water is at least few thousand years old. (author)

  15. Iron-mediated soil carbon response to water-table decline in an alpine wetland

    Science.gov (United States)

    Wang, Yiyun; Wang, Hao; He, Jin-Sheng; Feng, Xiaojuan

    2017-06-01

    The tremendous reservoir of soil organic carbon (SOC) in wetlands is being threatened by water-table decline (WTD) globally. However, the SOC response to WTD remains highly uncertain. Here we examine the under-investigated role of iron (Fe) in mediating soil enzyme activity and lignin stabilization in a mesocosm WTD experiment in an alpine wetland. In contrast to the classic `enzyme latch' theory, phenol oxidative activity is mainly controlled by ferrous iron [Fe(II)] and declines with WTD, leading to an accumulation of dissolvable aromatics and a reduced activity of hydrolytic enzyme. Furthermore, using dithionite to remove Fe oxides, we observe a significant increase of Fe-protected lignin phenols in the air-exposed soils. Fe oxidation hence acts as an `iron gate' against the `enzyme latch' in regulating wetland SOC dynamics under oxygen exposure. This newly recognized mechanism may be key to predicting wetland soil carbon storage with intensified WTD in a changing climate.

  16. Electrical Resistivity Imaging of Tidal Fluctuations in the Water Table at Inwood Hill Park, Manhattan

    Science.gov (United States)

    Kenyon, P. M.; Kassem, D.; Olin, A.; Nunez, J.; Smalling, A.

    2005-05-01

    Inwood Hill Park is located on the northern tip of Manhattan and has been extensively modified over the years by human activities. In its current form, it has a backbone of exposed or lightly covered bedrock along the Hudson River, adjacent to a flat area with two tidal inlets along the northern shore of Manhattan. The tidal motions in the inlets are expected to drive corresponding fluctuations in the water table along the borders of the inlets. In the Fall of 2002, a group of students from the Department of Earth and Atmospheric Sciences at the City College of New York studied these fluctuations. Electrical resistivity cross sections were obtained with a Syscal Kid Switch 24 resistivity meter during the course of a tidal cycle at three locations surrounding the westernmost inlet in the park. No change was seen over a tidal cycle at Site 1, possibly due to the effect of concrete erosion barriers which were located between the land and the water surrounding this site. Measurements at Site 2 revealed a small, regular change in the water table elevation of approximately 5 cm over the course of a tidal cycle. This site is inferred to rest on alluvial sediments deposited by a small creek. The cross sections taken at different times during a tidal cycle at Site 3 were the most interesting. They show a very heterogeneous subsurface, with water spurting between blocks of high resistivity materials during the rising portion of the cycle. A small sinkhole was observed on the surface of the ground directly above an obvious plume of water in the cross section. Park personnel confirmed that this sinkhole, like others scattered around this site, is natural and not due to recent construction activity. They also indicated that debris from the construction of the New York City subways may have been dumped in the area in the past. Our conclusion is that the tidal fluctuations at Site 3 are being channeled by solid blocks in the construction debris, and that the sinkholes currently

  17. Bathymetric maps and water-quality profiles of Table Rock and North Saluda Reservoirs, Greenville County, South Carolina

    Science.gov (United States)

    Clark, Jimmy M.; Journey, Celeste A.; Nagle, Doug D.; Lanier, Timothy H.

    2014-01-01

    Lakes and reservoirs are the water-supply source for many communities. As such, water-resource managers that oversee these water supplies require monitoring of the quantity and quality of the resource. Monitoring information can be used to assess the basic conditions within the reservoir and to establish a reliable estimate of storage capacity. In April and May 2013, a global navigation satellite system receiver and fathometer were used to collect bathymetric data, and an autonomous underwater vehicle was used to collect water-quality and bathymetric data at Table Rock Reservoir and North Saluda Reservoir in Greenville County, South Carolina. These bathymetric data were used to create a bathymetric contour map and stage-area and stage-volume relation tables for each reservoir. Additionally, statistical summaries of the water-quality data were used to provide a general description of water-quality conditions in the reservoirs.

  18. Effect of temperature, pH, and oxygen level on the multiplication of naturally occurring Legionella pneumophila in potable water.

    Science.gov (United States)

    Wadowsky, R M; Wolford, R; McNamara, A M; Yee, R B

    1985-05-01

    A water culture containing naturally occurring Legionella pneumophila and associated microbiota was maintained in the laboratory by serially transferring the culture in tap water which had been sterilized by membrane filtration. Successful maintenance of the water culture depended upon transferring the culture when the growth of L. pneumophila was in the late-exponential to early-stationary phase. The water culture was used as a source of naturally occurring bacteria to determine some of the parameters which affect the multiplication of L. pneumophila in tap water. Naturally occurring L. pneumophila multiplied at a temperature between 25 and 37 degrees C, at pH levels of 5.5 to 9.2, and at concentrations of dissolved oxygen of 6.0 to 6.7 mg/liter. Multiplication did not occur in tap water which contained less than 2.2 mg of dissolved oxygen per liter. An association was observed between the multiplication of L. pneumophila and the non-Legionellaceae bacteria which were also present in the water culture. The method of preserving naturally occurring L. pneumophila and associated microbiota may facilitate studies on the symbiosis of L. pneumophila with other microorganisms.

  19. Culture of microalgae biomass for valorization of table olive processing water

    International Nuclear Information System (INIS)

    Contreras, C.G.; Serrano, A.; Ruiz-Filippi, G.; Borja, R.; Fermoso, F.G.

    2016-01-01

    Table olive processing water (TOPW) contains many complex substances, such as phenols, which could be valorized as a substrate for microalgae biomass culture. The aim of this study was to assess the capability of Nannochloropsis gaditana to grow in TOPW at different concentrations (10- 80%) in order to valorize this processing water. Within this range, the highest increment of biomass was determined at percentage of 40% of TOPW, reaching an increment of 0.36 ± 0.05 mg volatile suspended solids (VSS)/L. Components of algal biomass were similar for the experiments at 10-40% of TOPW, where proteins were the major compounds (56-74%). Total phenols were retained in the microalgae biomass (0.020 ± 0.002 g of total phenols/g VSS). Experiments for 80% of TOPW resulted in a low production of microalgae biomass. High organic matter, nitrogen, phosphorus and phenol removal were achieved in all TOPW concentrations. Although high-value products, such as proteins, were obtained and high removal efficiencies of nutrients were determined, microalgae biomass culture should be enhanced to become a suitable integral processing water treatment. [es

  20. A Modified Water-Table Fluctuation Method to Characterize Regional Groundwater Discharge

    Directory of Open Access Journals (Sweden)

    Lihong Yang

    2018-04-01

    Full Text Available A modified Water-Table Fluctuation (WTF method is developed to quantitatively characterize the regional groundwater discharge patterns in stressed aquifers caused by intensive agricultural pumping. Two new parameters are defined to express the secondary information in the observed data. One is infiltration efficiency and the other is discharge modulus (recurring head loss due to aquifer discharge. An optimization procedure is involved to estimate these parameters, based on continuous groundwater head measurements and precipitation records. Using the defined parameters and precipitation time series, water level changes are calculated for individual wells with fidelity. The estimated parameters are then used to further address the characterization of infiltration and to better quantify the discharge at the regional scale. The advantage of this method is that it considers recharge and discharge simultaneously, whereas the general WTF methods mostly focus on recharge. In the case study, the infiltration efficiency reveals that the infiltration is regionally controlled by the intrinsic characteristics of the aquifer, and locally distorted by engineered hydraulic structures that alter surface water-groundwater interactions. The seasonality of groundwater discharge is characterized by the monthly discharge modulus. These results from individual wells are clustered into groups that are consistent with the local land use pattern and cropping structures.

  1. Effects of high-rate wastewater spray disposal on the water-table aquifer, Hilton Head Island, South Carolina

    Science.gov (United States)

    Speiran, G.K.

    1985-01-01

    A study by the U.S. Geological Survey from April 1982 through December 1983 evaluated the effects of high-rate disposal of treated wastewater on the water table aquifer, Hilton Head Island, South Carolina. Flooding of topographically low areas resulted from the application of 10.8 inches of wastewater in 10 days in January 1983. The water table remained 2-1/2 to 5-1/2 feet below land surface when wastewater was applied at rates of 5 inches per week in August and December 1983. (USGS)

  2. Ground-water sampling of the NNWSI (Nevada Nuclear Waste Storage Investigation) water table test wells surrounding Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Matuska, N.A.

    1988-12-01

    The US Geological Survey (USGS), as part of the Nevada Nuclear Waste Storage Investigation (NNWSI) study of the water table in the vicinity of Yucca Mountain, completed 16 test holes on the Nevada Test Site and Bureau of Land Management-administered lands surrounding Yucca Mountain. These 16 wells are monitored by the USGS for water-level data; however, they had not been sampled for ground-water chemistry or isotropic composition. As part of the review of the proposed Yucca Mountain high-level nuclear waste repository, the Desert Research Institute (DRI) sampled six of these wells. The goal of this sampling program was to measure field-dependent parameters of the water such as electrical conductivity, pH, temperature and dissolved oxygen, and to collect samples for major and minor element chemistry and isotopic analysis. This information will be used as part of a program to geochemically model the flow direction between the volcanic tuff aquifers and the underlying regional carbonate aquifer

  3. Naturally occurring radionuclides in materials derived from urban water treatment plants in southeast Queensland, Australia

    International Nuclear Information System (INIS)

    Kleinschmidt, Ross; Akber, Riaz

    2008-01-01

    An assessment of radiologically enhanced residual materials generated during treatment of domestic water supplies in southeast Queensland, Australia, was conducted. Radioactivity concentrations of U-238, Th-232, Ra-226, Rn-222, and Po-210 in water, sourced from both surface water catchments and groundwater resources were examined both pre- and post-treatment under typical water treatment operations. Surface water treatment processes included sedimentation, coagulation, flocculation and filtration, while the groundwater was treated using cation exchange, reverse osmosis, activated charcoal or methods similar to surface water treatment. Waste products generated as a result of treatment included sediments and sludges, filtration media, exhausted ion exchange resin, backwash and wastewaters. Elevated residual concentrations of radionuclides were identified in these waste products. The waste product activity concentrations were used to model the radiological impact of the materials when either utilised for beneficial purposes, or upon disposal. The results indicate that, under current water resource exploitation programs, reuse or disposal of the treatment wastes from large scale urban water treatment plants in Australia do not pose a significant radiological risk

  4. Water-use strategies in two co-occurring Mediterranean evergreen oaks: surviving the summer drought.

    Science.gov (United States)

    David, T S; Henriques, M O; Kurz-Besson, C; Nunes, J; Valente, F; Vaz, M; Pereira, J S; Siegwolf, R; Chaves, M M; Gazarini, L C; David, J S

    2007-06-01

    In the Mediterranean evergreen oak woodlands of southern Portugal, the main tree species are Quercus ilex ssp. rotundifolia Lam. (holm oak) and Quercus suber L. (cork oak). We studied a savannah-type woodland where these species coexist, with the aim of better understanding the mechanisms of tree adaptation to seasonal drought. In both species, seasonal variations in transpiration and predawn leaf water potential showed a maximum in spring followed by a decline through the rainless summer and a recovery with autumn rainfall. Although the observed decrease in predawn leaf water potential in summer indicates soil water depletion, trees maintained transpiration rates above 0.7 mm day(-1) during the summer drought. By that time, more than 70% of the transpired water was being taken from groundwater sources. The daily fluctuations in soil water content suggest that some root uptake of groundwater was mediated through the upper soil layers by hydraulic lift. During the dry season, Q. ilex maintained higher predawn leaf water potentials, canopy conductances and transpiration rates than Q. suber. The higher water status of Q. ilex was likely associated with their deeper root systems compared with Q. suber. Whole-tree hydraulic conductance and minimum midday leaf water potential were lower in Q. ilex, indicating that Q. ilex was more tolerant to drought than Q. suber. Overall, Q. ilex seemed to have more effective drought avoidance and drought tolerance mechanisms than Q. suber.

  5. Large-scale regionalization of water table depth in peatlands optimized for greenhouse gas emission upscaling

    Science.gov (United States)

    Bechtold, M.; Tiemeyer, B.; Laggner, A.; Leppelt, T.; Frahm, E.; Belting, S.

    2014-09-01

    Fluxes of the three main greenhouse gases (GHG) CO2, CH4 and N2O from peat and other soils with high organic carbon contents are strongly controlled by water table depth. Information about the spatial distribution of water level is thus a crucial input parameter when upscaling GHG emissions to large scales. Here, we investigate the potential of statistical modeling for the regionalization of water levels in organic soils when data covers only a small fraction of the peatlands of the final map. Our study area is Germany. Phreatic water level data from 53 peatlands in Germany were compiled in a new data set comprising 1094 dip wells and 7155 years of data. For each dip well, numerous possible predictor variables were determined using nationally available data sources, which included information about land cover, ditch network, protected areas, topography, peatland characteristics and climatic boundary conditions. We applied boosted regression trees to identify dependencies between predictor variables and dip-well-specific long-term annual mean water level (WL) as well as a transformed form (WLt). The latter was obtained by assuming a hypothetical GHG transfer function and is linearly related to GHG emissions. Our results demonstrate that model calibration on WLt is superior. It increases the explained variance of the water level in the sensitive range for GHG emissions and avoids model bias in subsequent GHG upscaling. The final model explained 45% of WLt variance and was built on nine predictor variables that are based on information about land cover, peatland characteristics, drainage network, topography and climatic boundary conditions. Their individual effects on WLt and the observed parameter interactions provide insight into natural and anthropogenic boundary conditions that control water levels in organic soils. Our study also demonstrates that a large fraction of the observed WLt variance cannot be explained by nationally available predictor variables and

  6. Environmental effects on stem water deficit in co-occurring conifers exposed to soil dryness

    Science.gov (United States)

    Oberhuber, Walter; Kofler, Werner; Schuster, Roman; Wieser, Gerhard

    2015-04-01

    We monitored dynamics of stem water deficit (Δ W) and needle water potential ( Ψ) during two consecutive growing seasons (2011 and 2012) in a dry inner Alpine environment (750 m above sea level, Tyrol, Austria), where Pinus sylvestris, Picea abies and Larix decidua form mixed stands. Δ W was extracted from stem circumference variations, which were continuously recorded by electronic band dendrometers (six trees per species) and correlations with environmental variables were performed. Results revealed that (i) Δ W reached highest and lowest values in P. abies and L. decidua, respectively, while mean minimum water potential ( Ψ ea) amounted to -3.0 MPa in L. decidua and -1.8 MPa in P. abies and P. sylvestris. (ii) Δ W and Ψ ea were significantly correlated in P. abies ( r = 0.630; P = 0.038) and L. decidua ( r = 0.646; P = 0.032). (iii) In all species, Δ W reached highest values in late summer and was most closely related to temperature ( P drought-sensitive L. decidua and drought-tolerant P. sylvestris indicate that various water storage locations are depleted in species showing different strategies of water status regulation, i.e. anisohydric vs. isohydric behavior, respectively, and/or water uptake efficiency differs among these species. Close coupling of Δ W to temperature suggests that climate warming affects plant water status through its effect on atmospheric demand for moisture.

  7. Upper Bound Solution for the Face Stability of Shield Tunnel below the Water Table

    Directory of Open Access Journals (Sweden)

    Xilin Lu

    2014-01-01

    Full Text Available By FE simulation with Mohr-Coulomb perfect elastoplasticity model, the relationship between the support pressure and displacement of the shield tunnel face was obtained. According to the plastic strain distribution at collapse state, an appropriate failure mechanism was proposed for upper bound limit analysis, and the formula to calculate the limit support pressure was deduced. The limit support pressure was rearranged to be the summation of soil cohesion c, surcharge load q, and soil gravity γ multiplied by their corresponding coefficients Nc, Nq, and Nγ, and parametric studies were carried out on these coefficients. In order to consider the influence of seepage on the face stability, the pore water pressure distribution and the seepage force on the tunnel face were obtained by FE simulation. After adding the power of seepage force into the equation of the upper bound limit analysis, the total limit support pressure for stabilizing the tunnel face under seepage condition was obtained. The total limit support pressure was shown to increase almost linearly with the water table.

  8. Naturally occurring radionuclides in drinking water before and after radon removal

    International Nuclear Information System (INIS)

    Swedjemark, G.A.; Linden, A.

    1998-06-01

    Radon removal can, with a good effect, be used to remove radon from well water. The short-lived radon progeny have been investigated in the raw and cleaned water from six private wells where radon removal based on aeration and recirculation of the water have been installed. The results from this pilot study indicate that the short-lived radon progeny in some cases follow the water to the tap for consumption to such an extent that the problem should be considered. The extent of the study is not sufficient for general conclusions. However, it is important to stress that the effective dose from the short-lived progeny is always lower than it would have been from the radon, when no radon is removed

  9. Review of research on impacts to biota of discharges of naturally occurring radionuclides in produced water to the marine environment

    International Nuclear Information System (INIS)

    Hosseini, Ali; Brown, Justin E.; Gwynn, Justin P.; Dowdall, Mark

    2012-01-01

    Produced water has been described as the largest volume waste stream in the exploration and production process of oil and gas. It is accompanied by discharges of naturally occurring radionuclides raising concerns over the potential radiological impacts of produced water on marine biota. In the Northern European marine environment, radioactivity in produced water has received substantial attention owing to the OSPAR Radioactive Substances Strategy which aims at achieving ‘concentrations in the environment near background values for naturally occurring radioactive substances’. This review provides an overview of published research on the impacts to biota from naturally occurring radionuclides discharged in produced water by the offshore oil and gas industry. In addition to summarising studies and data that deal directly with the issue of dose and effect, the review also considers studies related to the impact of added chemicals on the fate of discharged radionuclides. The review clearly illustrates that only a limited number of studies have investigated possible impacts on biota from naturally occurring radionuclides present in produced water. Hence, although these studies indicate that the risk to the environment from naturally occurring radionuclides discharged in produced water is negligible, the substantial uncertainties involved in the assessments of impact make it difficult to be conclusive. With regard to the complexity involved in the problem under consideration there is a pressing need to supplement existing data and acquire new knowledge. Finally, the present work identifies some knowledge gaps to indicate future research requirements. -- Highlights: ► Produced water from offshore oil industry contains naturally occurring radionuclides. ► Published research on the impacts to biota from these radionuclides is reviewed. ► Review includes impact of added chemicals on the fate of discharged radionuclides. ► Studies indicate negligible risk to biota

  10. Non-methane biogenic volatile organic compound emissions from boreal peatland microcosms under warming and water table drawdown

    DEFF Research Database (Denmark)

    Faubert, P; Tiiva, P; Nakam, TA

    2011-01-01

    assessed the combined effect of warming and water table drawdown on the BVOC emissions from boreal peatland microcosms. We also assessed the treatment effects on the BVOC emissions from the peat soil after the 7-week long experiment. Emissions of isoprene, monoterpenes, sesquiterpenes, other reactive VOCs...

  11. The leaching of radioactivity from highly radioactive glass blocks buried below the water table: fifteen years of results

    International Nuclear Information System (INIS)

    Merritt, W.F.

    1976-03-01

    The results from two test burials of high-level fission products incorporated into nepheline syenite glass indicate that the nuclear wastes from fuel processing for a 30,000 MWe nuclear power industry could be incorporated into such glass and stored beneath the water table in the waste management area of Chalk River Nuclear Laboratories (CRNL) without harm to the environment. (author)

  12. Water table response to harvesting and simulated emerald ash borer mortality in black ash wetlands in Minnesota, USA

    Science.gov (United States)

    Robert A. Slesak; Christian F. Lenhart; Kenneth N. Brooks; Anthony W. D' Amato; Brian J. Palik

    2014-01-01

    Black ash wetlands are seriously threatened because of the invasive emerald ash borer (EAB). Wetland hydrology is likely to be modified following ash mortality, but the magnitude of hydrological impact following loss via EAB and alternative mitigation harvests is not clear. Our objective was to assess the water table response to simulated EAB and harvesting to...

  13. Spectral detection of near-surface moisture content and water-table position in northern peatland ecosystems

    Science.gov (United States)

    Karl M. Meingast; Michael J. Falkowski; Evan S. Kane; Lynette R. Potvin; Brian W. Benscoter; Alistair M.S. Smith; Laura L. Bourgeau-Chavez; Mary Ellen. Miller

    2014-01-01

    Wildland fire occurrence has been increasing in peatland ecosystems during recent decades. As such, there is a need for broadly applicable tools to detect and monitor controls on combustion such as surface peat moisture and water-table position. A field portable spectroradiometer was used to measure surface reflectance of two Sphagnum moss-dominated...

  14. Ecosystem respiration in a heterogeneous temperate peatland and its sensitivity to peat temperature and water table depth

    Czech Academy of Sciences Publication Activity Database

    Juszczak, R.; Humphreys, E.; Acosta, Manuel; Michalak-Galczewska, M.; Kayzer, D.; Olejnik, Janusz

    2013-01-01

    Roč. 366, 1-2 (2013), s. 505-520 ISSN 0032-079X Institutional support: RVO:67179843 Keywords : Ecosystem respiration * Geogenous peatland * Chamber measurements * CO2 fluxes * Water table depth Subject RIV: EH - Ecology, Behaviour Impact factor: 3.235, year: 2013

  15. Interactive plant functional group and water table effects on decomposition and extracellular enzyme activity in Sphagnum peatlands

    Science.gov (United States)

    Magdalena M. Wiedermann; Evan S. Kane; Lynette R. Potvin; Erik A. Lilleskov

    2017-01-01

    Peatland decomposition may be altered by hydrology and plant functional groups (PFGs), but exactly how the latter influences decomposition is unclear, as are potential interactions of these factors.We used a factorial mesocosm experiment with intact 1 m3 peat monoliths to explore how PFGs (sedges vs Ericaceae) and water table level individually...

  16. LITHOLOGIC CONDITIONS OF THE WATER TABLE LOGGING IN THE AREA OF HAĆKI VILLAGE IN THE BIELSKA PLAIN

    Directory of Open Access Journals (Sweden)

    Krzysztof Micun

    2016-05-01

    Full Text Available The aim of the study was to examine lithological conditions of the water table in the area of Haćki village located in the Bielska Plain. The study involved the measurements of water level in dug wells, hand drill probing to a depth of 5 m, acquiring the samples of water-bearing deposits and analysing their granulation. The results of analyses allowed to calculate the permeability coefficient. The geological structure of the area is dominated by dusty deposits of various origins. Such deposits’ formation directly affects the conditions of filtration and depth of the water table. Groundwater logging near Haćki village in the Bielska Plain appears at a depth of several tens of centimeters to 2 meters in the depressions field and up a little over 5 meters in the case of higher ground surfaces. The presence of perched water was revealed on the hills, periodic leachates at the foot of the hills and scarps and one periodic spring. Water-bearing deposits are medium sands, fine sands and loamy fine sands or fine sands with silt. Consequently, the permeability coefficient is low or even very low. Its values range from 0,001 m·d-1 to 3,8 m·d-1 (d – 24 hours. The widespread presence of dusty deposits in the area affects the limited efficiency of the water table.

  17. The prevalence of fluorosis in children is associated with naturally occurring water fluoride concentration in Mexico.

    Science.gov (United States)

    Mariño, Rodrigo

    2013-09-01

    Fluorosis and dental caries in Mexican schoolchildren residing in areas with different water fluoride concentrations and receiving fluoridated salt. Garcia-Perez A, Irigoyen-Carnacho ME, Borges-Yanez A. Caries Res 2013;47(4):299-308. Rodrigo Mariño Is there an association between the presence of dental fluorosis and fluoride concentration in drinking water? and Is there an association between the severity of fluorosis and dental caries experience in schoolchildren residing in two rural towns in Mexico (with water fluoride concentrations of 0.70 and 1.50 ppm) that also receive fluoridated salt? Government: National Council of Science and Technology (Consejo Nacional de Ciencia y Tecnologia, CONACYT) Other: Autonomous University, Xochimilco (Universidad Autonoma Metropolitana, UAM-X) TYPE OF STUDY/DESIGN: Cross-sectional Level 3: Other evidence Not applicable. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Occurence of Cryptosporidium spp. in low quality water and on vegetables in Kumasi, Ghana

    DEFF Research Database (Denmark)

    Petersen, T. B.; Petersen, H. H.; Abaidoo, R. C.

    2014-01-01

    Protozoan parasites belonging to the genus Cryptosporidium are transmitted e.g. by food and water and may cause severe diarrhoea, dehydration, weight loss and malnutrition. Ingestion of 10 oocysts can lead to infection and pathogenic symptoms. Thus, to characterize Cryptosporidium spp. contaminat......Protozoan parasites belonging to the genus Cryptosporidium are transmitted e.g. by food and water and may cause severe diarrhoea, dehydration, weight loss and malnutrition. Ingestion of 10 oocysts can lead to infection and pathogenic symptoms. Thus, to characterize Cryptosporidium spp...... of Cryptosporidium positive samples was unsuccessful, thus no conclusions can be drawn concerning sources of contamination. Nevertheless, the detection of high prevalence and concentration levels of Cryptosporidium oocysts on vegetables consumed raw and in water with direct contact to humans entails a potential risk...

  19. Basic prerequisites and the practice of using deep water tables for burying liquid radioactive wastes

    International Nuclear Information System (INIS)

    Spitsyn, V.I.; Pimenov, M.K.; Balukova, V.D.; Leontichuk, A.S.; Kokorin, I.N.; Yudin, F.P.; Rakov, N.A.

    In the USSR, creating reservoirs for liquid radioactive wastes is one of the promising methods of safely disposing of them in deep water tables, in zones with a standing regime or a slow rate of subterranean water exchange. The results of investigations and the practice of burying (the wastes) indicate the reliability and effectiveness of such a method of final waste disposal when the basic requirements of environmental protection are observed. Geological formations and collector strata that guarantee the localization of the liquid radioactive wastes placed in them for many tens and even hundreds of thousands of years can be studied and chosen in different regions. The basic requirements and criteria to which the geological structures and collector strata must correspond for ensuring the safe burial of wastes have been formulated. Wastes are buried only after a comprehensive, scientifically based evaluation of the sanitary-radiation safety for this generation and future ones, taking into account the burial regime and the physico-chemical processes that accompany combining wastes with rocks and stratal waters, as well as the time of holding wastes to maximum permissible concentrations. Positive and negative factors that characterize the method are analyzed. Possible emergency situations with subterranean burial are evaluated. The composition and methods of the geological survey, hydrodynamic, geophysical, physico-chemical and sanitary-radiation investigations; methods of calculating and predicting the movement of wastes underground;methods of preparing wastes for burial and chemical methods of restoring the suitability of wells; design characteristics and conditions of preparing wells for use; methods of estimating heating and processes of radiolysis for a medium containing highly radioactive wastes; methods of operational and remote control of the burial process and the condition of the ambient medium, etc. are briefly examined

  20. Naturally occurring radionuclides in food and drinking water from a thorium-rich area

    International Nuclear Information System (INIS)

    Costa Lauria, Dejanira da; Rochedo, Elaine R.R.; Godoy, Maria Luisa D.P.; Santos, Eliane E.; Hacon, Sandra S.

    2012-01-01

    This paper focuses on a survey of uranium and thorium decay chain radionuclides in food and drinking water from the thorium-rich (monazite-bearing) region of Buena, which is located in the state of Rio de Janeiro, Brazil. The radionuclide concentration values in the food and drinking water from Buena reached values higher than 100-fold the international reference values. The daily intake of radionuclides by the local population is similar to that of another high background radiation area in Brazil, but the intake is higher than that of residents from a normal background radiation area. Approximately 58 % of the food consumed by Buena inhabitants is produced locally. Based on that figure, locally produced food and the dilution of total radionuclides in the diet of residents caused by food importation are both highly relevant to a population's intake of radionuclides. The concentration values for 210 Pb and the radium isotopes in drinking water from Buena are among the highest values to be reported in the literature. 228 Ra is the most important radionuclide ingested with both food and water among the inhabitants of Buena. (orig.)

  1. The impact of long-term changes in water table height on carbon cycling in sub-boreal peatlands

    Science.gov (United States)

    Pypker, T. G.; Moore, P. A.; Waddington, J. M.; Hribljan, J. A.; Ballantyne, D.; Chimner, R. A.

    2011-12-01

    Peatlands are a critical component in the global carbon (C) cycle because they have been slowly sequestering atmospheric greenhouse gases as peat since the last glaciation. Today, soil C stocks in peatlands are estimated to represent 224 to 455 Pg, equal to 12-30% of the global soil C pool. At present, peatlands are estimated to sequester 76 Tg C yr-1. The flux of C to and from peatlands is likely to respond to climate change, thereby influencing atmospheric C concentrations. Peatland C budgets are tightly linked to their hydrology, hence, it is critical we understand how changes in hydrology will affect the C budgets of peatlands. The main objective of the project was to determine how long-term changes in water table height affect CO2 and CH4 fluxes from three adjacent peatlands. This study took place in the Seney National Wildlife Refuge (SNWR) in the Upper Peninsula of Michigan. SNWR is home to the largest wetland drainage project in Michigan. In 1912, ditches and dikes were created in an effort to convert approximately 20,000 ha of peatland to agriculture. The ditches and dikes were unsuccessful in creating agricultural land, but they are still in place. The manipulation of water table heights provides an opportunity to research how long-term peat drying or wetting alters C cycling in peatlands. From May to November in 2009, 2010 and 2011, we monitored CO2 fluxes using eddy covariance and chamber techniques in three adjacent peatlands with lowered, relatively unaltered ("control") and raised water table heights. In 2011, we installed CH4 analyzers to continuously monitor CH4 fluxes at the sites with high and relatively unaltered water table heights. The results are compared across sites to determine how changes in water table height might affect C fluxes sub-boreal peatlands.

  2. Water hammer phenomena occurring in nuclear power installations while filling horizontal pipe containing saturated steam with liquid

    Energy Technology Data Exchange (ETDEWEB)

    Selivanov, Y.F.; Kirillov, P.L.; Yefanov, A.D. [Institute of Physics and Power Engineering, Obninsk (Russian Federation)

    1995-09-01

    The potentiality of the water hammer occurrence in nuclear reactor loop components has been considered under the conditions of filling a steam-containing pipeline leg involving horizontal and vertical sections with liquid subcooled to the saturation temperature. As a result of free discharging from the tank, the liquid enters the horizontal pipeline. When the liquid slug formation in the pipeline is fulfilled. The pressure drop being occurred in steam flowing along the pipelines causes the liquid slug to move to the pipeline inlet. When the liquid slug decelerates, a water hammer occurs. This mechanism of water hammer occurrence is tested by experiments. The regimes of the occurrence of multiple considerable water hammers were identified.

  3. Water hammer phenomena occurring in nuclear power installations while filling horizontal pipe containing saturated steam with liquid

    International Nuclear Information System (INIS)

    Selivanov, Y.F.; Kirillov, P.L.; Yefanov, A.D.

    1995-01-01

    The potentiality of the water hammer occurrence in nuclear reactor loop components has been considered under the conditions of filling a steam-containing pipeline leg involving horizontal and vertical sections with liquid subcooled to the saturation temperature. As a result of free discharging from the tank, the liquid enters the horizontal pipeline. When the liquid slug formation in the pipeline is fulfilled. The pressure drop being occurred in steam flowing along the pipelines causes the liquid slug to move to the pipeline inlet. When the liquid slug decelerates, a water hammer occurs. This mechanism of water hammer occurrence is tested by experiments. The regimes of the occurrence of multiple considerable water hammers were identified

  4. Holes in the Bathtub: Water Table Dependent Services and Threshold Behavior in an Economic Model of Groundwater Extraction

    Science.gov (United States)

    Kirk-lawlor, N. E.; Edwards, E. C.

    2012-12-01

    In many groundwater systems, the height of the water table must be above certain thresholds for some types of surface flow to exist. Examples of flows that depend on water table elevation include groundwater baseflow to river systems, groundwater flow to wetland systems, and flow to springs. Meeting many of the goals of sustainable water resource management requires maintaining these flows at certain rates. Water resource management decisions invariably involve weighing tradeoffs between different possible usage regimes and the economic consequences of potential management choices are an important factor in these tradeoffs. Policies based on sustainability may have a social cost from forgoing present income. This loss of income may be worth bearing, but should be well understood and carefully considered. Traditionally, the economic theory of groundwater exploitation has relied on the assumption of a single-cell or "bathtub" aquifer model, which offers a simple means to examine complex interactions between water user and hydrologic system behavior. However, such a model assumes a closed system and does not allow for the simulation of groundwater outflows that depend on water table elevation (e.g. baseflow, springs, wetlands), even though those outflows have value. We modify the traditional single-cell aquifer model by allowing for outflows when the water table is above certain threshold elevations. These thresholds behave similarly to holes in a bathtub, where the outflow is a positive function of the height of the water table above the threshold and the outflow is lost when the water table drops below the threshold. We find important economic consequences to this representation of the groundwater system. The economic value of services provided by threshold-dependent outflows (including non-market value), such as ecosystem services, can be incorporated. The value of services provided by these flows may warrant maintaining the water table at higher levels than would

  5. Influence of Asellus aquaticus on Escherichia coli, Klebsiella pneumoniae, Campylobacter jejuni and naturally occurring heterotrophic bacteria in drinking water.

    Science.gov (United States)

    Christensen, Sarah C B; Nissen, Erling; Arvin, Erik; Albrechtsen, Hans-Jørgen

    2012-10-15

    Water lice, Asellus aquaticus (isopoda), frequently occur in drinking water distribution systems where they are a nuisance to consumers and water utilities. Whether they are solely an aesthetic problem or also affect the microbial water quality is a matter of interest. We studied the influence of A. aquaticus on microbial water quality in non-chlorinated drinking water in controlled laboratory experiments. Pure cultures of the indicator organisms Escherichia coli and Klebsiella pneumoniae and the pathogen Campylobacter jejuni as well as naturally occurring heterotrophic drinking water bacteria (measured as heterotrophic plate counts, HPC) were investigated in microcosms at 7 °C, containing non-sterilised drinking water, drinking water sediment and A. aquaticus collected from a non-chlorinated ground water based drinking water supply system. Concentrations of E. coli, K. pneumoniae and C. jejuni decreased over time, following a first order decay with half lives of 5.3, 18.4 and 1.3 days, respectively. A. aquaticus did not affect survival of indicators and pathogens substantially whereas HPC were influenced by presence of dead A. aquaticus. Growth rates increased with an average of 48% for bacteria grown on R-2A agar and an average of 83% for bacteria grown on yeast extract agar when dead A. aquaticus were present compared to no and living A. aquaticus present. A. aquaticus associated E. coli, K. pneumoniae and C. jejuni were measured (up to 25 per living and 500 per dead A. aquaticus) and so were A. aquaticus associated heterotrophic bacteria (>1.8*10(4) CFU per living and >6*10(4) CFU per dead A. aquaticus). A. aquaticus did not serve as an optimised habitat that increased survival of indicators and pathogens, since A. aquaticus associated E. coli, K. pneumoniae and C. jejuni were only measured as long as the bacteria were also present in the water and sediment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Properties of waste stillage from shochu distillery and waste water occurred sosei paper production process

    OpenAIRE

    山内, 正仁; 平田, 登基男; 前野, 祐二; 三原, めぐみ; 松藤, 康司

    1999-01-01

    As an effective utilization of waste stillage, which will be banned from being dumped into sea from the year of 2001, authors have been studied and succeeded to make the sosei paper by using waste stillage form shochu distillery. This research is tried to consider the property of waste stillage from shochu distillery ( sweet potato waste stillage and barley waste stillage) and the weight and property of waste water in compressing samples added some amount of old newspaper to waste stillage. F...

  7. Effects of water table position and plant functional group on plant community, aboveground production, and peat properties in a peatland mesocosm experiment (PEATcosm)

    Science.gov (United States)

    Lynette R. Potvin; Evan S. Kane; Rodney A. Chimner; Randall K. Kolka; Erik A. Lilleskov

    2015-01-01

    Aims Our objective was to assess the impacts of water table position and plant functional type on peat structure, plant community composition and aboveground plant production. Methods We initiated a full factorial experiment with 2 water table (WT) treatments (high and low) and 3 plant functional groups (PFG: sedge, Ericaceae,...

  8. Estimating evapotranspiration and groundwater flow from water-table fluctuations for a general wetland scenario

    Science.gov (United States)

    Weber, Lisa C.; Wiley, Michael J.; Wilcox, Douglas A.

    2016-01-01

    The use of diurnal water-table fluctuation methods to calculate evapotranspiration (ET) and groundwater flow is of increasing interest in ecohydrological studies. Most studies of this type, however, have been located in riparian wetlands of semi-arid regions where groundwater levels are consistently below topographic surface elevations and precipitation events are infrequent. Current methodologies preclude application to a wider variety of wetland systems. In this study, we extended a method for estimating sub-daily ET and groundwater flow rates from water-level fluctuations to fit highly dynamic, non-riparian wetland scenarios. Modifications included (1) varying the specific yield to account for periodic flooded conditions and (2) relating empirically derived ET to estimated potential ET for days when precipitation events masked the diurnal signal. To demonstrate the utility of this method, we estimated ET and groundwater fluxes over two growing seasons (2006–2007) in 15 wetlands within a ridge-and-swale wetland complex of the Laurentian Great Lakes under flooded and non-flooded conditions. Mean daily ET rates for the sites ranged from 4.0 mm d−1 to 6.6 mm d−1. Shallow groundwater discharge rates resulting from evaporative demand ranged from 2.5 mm d−1 to 4.3 mm d−1. This study helps to expand our understanding of the evapotranspirative demand of plants under various hydrologic and climate conditions. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  9. Methane transport and emissions from soil as affected by water table and vascular plants.

    Science.gov (United States)

    Bhullar, Gurbir S; Iravani, Majid; Edwards, Peter J; Olde Venterink, Harry

    2013-09-08

    The important greenhouse gas (GHG) methane is produced naturally in anaerobic wetland soils. By affecting the production, oxidation and transport of methane to the atmosphere, plants have a major influence upon the quantities emitted by wetlands. Different species and functional plant groups have been shown to affect these processes differently, but our knowledge about how these effects are influenced by abiotic factors such as water regime and temperature remains limited. Here we present a mesocosm experiment comparing eight plant species for their effects on internal transport and overall emissions of methane under contrasting hydrological conditions. To quantify how much methane was transported internally through plants (the chimney effect), we blocked diffusion from the soil surface with an agar seal. We found that graminoids caused higher methane emissions than forbs, although the emissions from mesocosms with different species were either lower than or comparable to those from control mesocosms with no plant (i.e. bare soil). Species with a relatively greater root volume and a larger biomass exhibited a larger chimney effect, though overall methane emissions were negatively related to plant biomass. Emissions were also reduced by lowering the water table. We conclude that plant species (and functional groups) vary in the degree to which they transport methane to the atmosphere. However, a plant with a high capacity to transport methane does not necessarily emit more methane, as it may also cause more rhizosphere oxidation of methane. A shift in plant species composition from graminoids to forbs and/or from low to high productive species may lead to reduction of methane emissions.

  10. COMPUTATIONAL STUDY OF INTERSTELLAR GLYCINE FORMATION OCCURRING AT RADICAL SURFACES OF WATER-ICE DUST PARTICLES

    International Nuclear Information System (INIS)

    Rimola, Albert; Sodupe, Mariona; Ugliengo, Piero

    2012-01-01

    Glycine is the simplest amino acid, and due to the significant astrobiological implications that suppose its detection, the search for it in the interstellar medium (ISM), meteorites, and comets is intensively investigated. In the present work, quantum mechanical calculations based on density functional theory have been used to model the glycine formation on water-ice clusters present in the ISM. The removal of either one H atom or one electron from the water-ice cluster has been considered to simulate the effect of photolytic radiation and of ionizing particles, respectively, which lead to the formation of OH . radical and H 3 O + surface defects. The coupling of incoming CO molecules with the surface OH . radicals on the ice clusters yields the formation of the COOH . radicals via ZPE-corrected energy barriers and reaction energies of about 4-5 kcal mol –1 and –22 kcal mol –1 , respectively. The COOH . radicals couple with incoming NH=CH 2 molecules (experimentally detected in the ISM) to form the NHCH 2 COOH . radical glycine through energy barriers of 12 kcal mol –1 , exceedingly high at ISM cryogenic temperatures. Nonetheless, when H 3 O + is present, one proton may be barrierless transferred to NH=CH 2 to give NH 2 =CH 2 + . This latter may react with the COOH . radical to give the NH 2 CH 2 COOH +. glycine radical cation which can then be transformed into the NH 2 CHC(OH) 2 +. species (the most stable form of glycine in its radical cation state) or into the NH 2 CHCOOH . neutral radical glycine. Estimated rate constants of these events suggest that they are kinetically feasible at temperatures of 100-200 K, which indicate that their occurrence may take place in hot molecular cores or in comets exposed to warmer regions of solar systems. Present results provide quantum chemical evidence that defects formed on water ices due to the harsh-physical conditions of the ISM may trigger reactions of cosmochemical interest. The relevance of surface H 3 O

  11. Computational Study of Interstellar Glycine Formation Occurring at Radical Surfaces of Water-ice Dust Particles

    Science.gov (United States)

    Rimola, Albert; Sodupe, Mariona; Ugliengo, Piero

    2012-07-01

    Glycine is the simplest amino acid, and due to the significant astrobiological implications that suppose its detection, the search for it in the interstellar medium (ISM), meteorites, and comets is intensively investigated. In the present work, quantum mechanical calculations based on density functional theory have been used to model the glycine formation on water-ice clusters present in the ISM. The removal of either one H atom or one electron from the water-ice cluster has been considered to simulate the effect of photolytic radiation and of ionizing particles, respectively, which lead to the formation of OH• radical and H3O+ surface defects. The coupling of incoming CO molecules with the surface OH• radicals on the ice clusters yields the formation of the COOH• radicals via ZPE-corrected energy barriers and reaction energies of about 4-5 kcal mol-1 and -22 kcal mol-1, respectively. The COOH• radicals couple with incoming NH=CH2 molecules (experimentally detected in the ISM) to form the NHCH2COOH• radical glycine through energy barriers of 12 kcal mol-1, exceedingly high at ISM cryogenic temperatures. Nonetheless, when H3O+ is present, one proton may be barrierless transferred to NH=CH2 to give NH2=CH2 +. This latter may react with the COOH• radical to give the NH2CH2COOH+• glycine radical cation which can then be transformed into the NH2CHC(OH)2 +• species (the most stable form of glycine in its radical cation state) or into the NH2CHCOOH• neutral radical glycine. Estimated rate constants of these events suggest that they are kinetically feasible at temperatures of 100-200 K, which indicate that their occurrence may take place in hot molecular cores or in comets exposed to warmer regions of solar systems. Present results provide quantum chemical evidence that defects formed on water ices due to the harsh-physical conditions of the ISM may trigger reactions of cosmochemical interest. The relevance of surface H3O+ ions to facilitate chemical

  12. COMPUTATIONAL STUDY OF INTERSTELLAR GLYCINE FORMATION OCCURRING AT RADICAL SURFACES OF WATER-ICE DUST PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Rimola, Albert; Sodupe, Mariona [Departament de Quimica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Ugliengo, Piero, E-mail: albert.rimola@uab.cat [Dipartimento di Chimica, NIS Centre of Excellence and INSTM (Materials and Technology National Consortium), UdR Torino, Universita di Torino, Via P. Giuria 7, 10125 Torino (Italy)

    2012-07-20

    Glycine is the simplest amino acid, and due to the significant astrobiological implications that suppose its detection, the search for it in the interstellar medium (ISM), meteorites, and comets is intensively investigated. In the present work, quantum mechanical calculations based on density functional theory have been used to model the glycine formation on water-ice clusters present in the ISM. The removal of either one H atom or one electron from the water-ice cluster has been considered to simulate the effect of photolytic radiation and of ionizing particles, respectively, which lead to the formation of OH{sup .} radical and H{sub 3}O{sup +} surface defects. The coupling of incoming CO molecules with the surface OH{sup .} radicals on the ice clusters yields the formation of the COOH{sup .} radicals via ZPE-corrected energy barriers and reaction energies of about 4-5 kcal mol{sup -1} and -22 kcal mol{sup -1}, respectively. The COOH{sup .} radicals couple with incoming NH=CH{sub 2} molecules (experimentally detected in the ISM) to form the NHCH{sub 2}COOH{sup .} radical glycine through energy barriers of 12 kcal mol{sup -1}, exceedingly high at ISM cryogenic temperatures. Nonetheless, when H{sub 3}O{sup +} is present, one proton may be barrierless transferred to NH=CH{sub 2} to give NH{sub 2}=CH{sub 2}{sup +}. This latter may react with the COOH{sup .} radical to give the NH{sub 2}CH{sub 2}COOH{sup +.} glycine radical cation which can then be transformed into the NH{sub 2}CHC(OH){sub 2}{sup +.} species (the most stable form of glycine in its radical cation state) or into the NH{sub 2}CHCOOH{sup .} neutral radical glycine. Estimated rate constants of these events suggest that they are kinetically feasible at temperatures of 100-200 K, which indicate that their occurrence may take place in hot molecular cores or in comets exposed to warmer regions of solar systems. Present results provide quantum chemical evidence that defects formed on water ices due to the harsh

  13. [The marketing evaluation of the consumers' preference as regards the use of medicinal and medicinal table mineral waters].

    Science.gov (United States)

    Babaskin, D V; Babaskina, L I; Pavlova, A V

    2017-12-28

    The development of modern technologies in physiotherapy with the use of mineral waters, the expansion of the assortment of the medicinal and medicinal table waters as well as increasing the competitive advantages of domestic products require the more extensive marketing survey of the consumers' preferences in the market of mineral waters. The objective of the present study was the marketing evaluation of the consumers' preference in the segment of medicinal and medicinal table mineral waters in the city of Moscow. The survey involved 697 consumers of medicinal and medicinal table mineral waters. The sampling was carried out by the deterministic quota method. The field research was conducted by means of personal verbal interviews (32%) and the CATI to Web method (phone recruiting and on-line questioning) (68%) with the use of the structured questionnaire. Positioning was carried out making use of the two-dimensional schematic map and scoring assessment on an individual basis with calculation of integrated indicators. The marketing evaluation has demonstrated that the principal motive for purchasing mineral waters in more than 40% of respondents was the treatment and prevention of various diseases including disturbances in the urogenital system as well as digestive and respiratory disorders that appear to be the most frequent reasons for the consumption of mineral waters. The main factors that form the preferences of the consumers as regards the use of a concrete variety of mineral waters were elucidated. Of crucial importance for approximately 40% of the consumers (p<0.01) proved to be their health condition, the medical indications, and the available information about the therapeutic effectiveness of one or another type of mineral waters. Other factors were the quality of mineral water, its cost, the manufacturer and/or place of production, the attractiveness of the packaging, etc. The evaluation of the positioning of the mineral water consumers' preferences made

  14. Local two-phase modeling of the water-steam flows occurring in steam generators

    International Nuclear Information System (INIS)

    Denefle, Romain

    2013-01-01

    The present study is related to the need of modeling the two-phase flows occurring in a steam generator (liquid at inlet and vapour at outlet). The choice is made to investigate a hybrid modeling of the flow, considering the gas phase as two separated fields, each one being modeled with different closure laws. In so doing, the small and spherical bubbles are modeled through a dispersed approach within the two-fluid model, and the distorted bubbles are simulated with an interface locating method. The main outcome is about the implementation, the verification and the validation of the model dedicated to the large and distorted bubbles, as well as the coupling of the two approaches for the gas, allowing the presentation of demonstration calculations using the so-called hybrid approach. (author)

  15. Water Table Depth Reconstruction in Ombrotrophic Peatlands Using Biomarker Abundance Ratios and Compound-Specific Hydrogen Isotope Composition

    Science.gov (United States)

    Nichols, J. E.; Jackson, S. T.; Booth, R. K.; Pendall, E. G.; Huang, Y.

    2005-12-01

    Sediment cores from ombrotrophic peat bogs provide sensitive records of changes in precipitation/evaporation (P/E) balance. Various proxies have been developed to reconstruct surface moisture conditions in peat bogs, including testate amoebae, plant macrofossils, and peat humification. Studying species composition of testate amoeba assemblages is time consuming and requires specialized training. Humification index can be influenced by environmental factors other than moisture balance. The plant macrofossil proxy is less quantitative and cannot be performed on highly decomposed samples. We demonstrate that the ratio of C23 alkane to C29 alkane abundance may provide a simple alternative or complementary means of tracking peatland water-table depth. Data for this proxy can be collected quickly using a small sample (100 mg dry). Water-table depth decreases during drought, and abundance of Sphagnum, the dominant peat-forming genus, decreases as vascular plants increase. Sphagnum moss produces mainly medium chain-length alkanes (C21-C25) while vascular plants (grasses and shrubs) produce primarily longer chain-length alkanes (C27-C31). Therefore, C23:C29 n-alkane ratios quantitatively track the water table depth fluctuations in peat bogs. We compared C23:C29 n-alkane ratios in a core from Minden Bog (southeastern Michigan) with water table depth reconstructions based on testate-amoeba assemblages and humification. The 184-cm core spans the past ~3kyr of continuous peat deposition in the bog. Our results indicate that the alkane ratios closely track the water table depth variations, with C29 most abundant during droughts. We also explored the use of D/H ratios in Sphagnum biomarkers as a water-table depth proxy. Compound-specific hydrogen isotope ratio analyses were performed on Sphagnum biomarkers: C23 and C25 alkane and C24 acid. Dry periods are represented in these records by an enrichment of deuterium in these Sphagnum-specific compounds. These events also correlate

  16. Risk assessment from intake of Naturally Occuring Radioactive Materials in some bottled drinking water on the Ghanaian market

    International Nuclear Information System (INIS)

    Portuphy, M. O.

    2015-07-01

    Activity concentrations of the Naturally Occurring Radioactive Materials (NORMs) in some bottled water brands were analyzed using gamma spectrometry. 40 K activity concentrations were in the range of 3.57-5.47Bq/L, the highest occurring in brand L9. Similarly 232 Th activity concentrations were in the range of 0.30-0.56 Bq/L with the highest occurring in brand L8. 226 Ra was identified in eleven brands with the remaining five below detection limit. The highest value (0.53Bq/L) occurred in brand L9. Comparison of the mean concentrations showed significant differences at (α=0.05) between the various brands of bottled water. Estimated committed effective doses were generally below 0.1mSv/a for all age groups with the exception of children <1yr. Estimated lifetime cancer and hereditary risk was done using the ICRP risk assessment methodology. Relationship between Activity concentrations and some physicochemical parameters were established using scatter graphs. The significant one was the conductivity parameter and how estimated activity concentrations tend to correlate (Jobbàgy et al, 2013). Trace elements and heavy metals were analysed using titrimetry, UV-VIS spectroscopy and atomic absorption spectroscopy. Their levels were below recommended and conventional levels. Conclusively bottled water brands analyzed were therefore radiologically safe. (au)

  17. Fuzzy rule-based modelling for human health risk from naturally occurring radioactive materials in produced water

    International Nuclear Information System (INIS)

    Shakhawat, Chowdhury; Tahir, Husain; Neil, Bose

    2006-01-01

    Produced water, discharged from offshore oil and gas operations, contains chemicals from formation water, condensed water, and any chemical added down hole or during the oil/water separation process. Although, most of the contaminants fall below the detection limits within a short distance from the discharge port, a few of the remaining contaminants including naturally occurring radioactive materials (NORM) are of concern due to their bioavailability in the media and bioaccumulation characteristics in finfish and shellfish species used for human consumption. In the past, several initiatives have been taken to model human health risk from NORM in produced water. The parameters of the available risk assessment models are imprecise and sparse in nature. In this study, a fuzzy possibilistic evaluation using fuzzy rule based modeling has been presented. Being conservative in nature, the possibilistic approach considers possible input parameter values; thus provides better environmental prediction than the Monte Carlo (MC) calculation. The uncertainties of the input parameters were captured with fuzzy triangular membership functions (TFNs). Fuzzy if-then rules were applied for input concentrations of two isotopes of radium, namely 226 Ra, and 228 Ra, available in produced water and bulk dilution to evaluate the radium concentration in fish tissue used for human consumption. The bulk dilution was predicted using four input parameters: produced water discharge rate, ambient seawater velocity, depth of discharge port and density gradient. The evaluated cancer risk shows compliance with the regulatory guidelines; thus minimum risk to human health is expected from NORM components in produced water

  18. [Effects of water table manipulation on leaf photosynthesis, morphology and growth of Phragmites australis and Imperata cylindrica in the reclaimed tidal wetland at Dongtan of Chongming Island, China].

    Science.gov (United States)

    Zhong, Qi-Cheng; Wang, Jiang-Tao; Zhou, Jian-Hong; Ou, Qiang; Wang, Kai-Yun

    2014-02-01

    During the growing season of 2011, the leaf photosynthesis, morphological and growth traits of Phragmites australis and Imperata cylindrica were investigated along a gradient of water table (low, medium and high) in the reclaimed tidal wetland at the Dongtan of Chongming Island in the Yangtze Estuary of China. A series of soil factors, i. e., soil temperature, moisture, salinity and inorganic nitrogen content, were also measured. During the peak growing season, leaf photosynthetic capacity of P. australis in the wetland with high water table was significantly lower than those in the wetland with low and medium water tables, and no difference was observed in leaf photosynthetic capacity of I. cylindrica at the three water tables. During the entire growing season, at the shoot level, the morphological and growth traits of P. australis got the optimum in the wetland with medium water table, but most of the morphological and growth traits of I. cylindrica had no significant differences at the three water tables. At the population level, the shoot density, leaf area index and aboveground biomass per unit area were the highest in the wetland with high water table for P. australis, but all of the three traits were the highest in the wetland with low water table for I. cylindrica. At the early growing season, the rhizome biomass of P. australis in the 0-20 cm soil layer had no difference at the three water tables, and the rhizome biomass of I. cylindrica in the 0-20 cm soil layer in the wetland with high water table was significantly lower than those in the wetland with low and medium water table. As a native hygrophyte before the reclamation, the variations of performances of P. australis at the three water tables were probably attributed to the differences in the soil factors as well as the intensity of competition from I. cylindrica. To appropriately manipulate water table in the reclaimed tidal wetland may restrict the growth and propagation of the mesophyte I

  19. Water relations and foliar isotopic composition of Prosopis tamarugo Phil. an endemic tree of the Atacama Desert growing under three levels of water table depth.

    Directory of Open Access Journals (Sweden)

    Marco eGarrido

    2016-03-01

    Full Text Available Prosopis tamarugo Phil. is a strict phreatophyte tree species endemic to the Pampa del Tamarugal, Atacama Desert. The extraction of water for various uses has increased the depth of the water table in the Pampa aquifers threatening its conservation. This study aimed to determine the effect of the groundwater table depth on the water relations of P. tamarugo and to present thresholds of groundwater depth (GWD that can be used in the groundwater management of the P. tamarugo ecosystem. Three levels of GWD, 11.2 ± 0.3 m, 10.3 ± 0.3 m and 7.1 ± 0.1 m, (the last GWD being our reference were selected and groups of 4 individuals per GWD were studied in the months of January and July of the years 2011 through 2014. When the water table depth exceeded 10 m, P. tamarugo had lower pre-dawn and midday water potential but no differences were observed in minimum leaf stomatal resistance when compared to the condition of 7.1 m GWD; the leaf tissue increased its δ13C and δ18O composition. Furthermore, a smaller green canopy fraction of the trees and increased foliage loss in winter with increasing water table depth was observed. The differences observed in the physiological behavior of P. tamarugo trees, attributable to the ground water depth; show that increasing the depth of the water table from 7 to 11 m significantly affects the water status of P. tamarugo. The results indicate that P. tamarugo has an anisohydric stomatal behaviour and that given a reduction in water supply it regulates the water demand via foliage loss. The growth and leaf physiological activities are highly sensitive to GWD. The foliage loss appears to prevent the trees from reaching water potentials leading to complete loss of hydraulic functionality by cavitation. The balance achieved between water supply and demand was reflected in the low variation of the water potential and of the variables related to gas exchange over time for a given GWD. This acclimation capacity of P

  20. Water Relations and Foliar Isotopic Composition of Prosopis tamarugo Phil., an Endemic Tree of the Atacama Desert Growing at Three Levels of Water Table Depth.

    Science.gov (United States)

    Garrido, Marco; Silva, Paola; Acevedo, Edmundo

    2016-01-01

    Prosopis tamarugo Phil. is a strict phreatophyte tree species endemic to the "Pampa del Tamarugal", Atacama Desert. The extraction of water for various uses has increased the depth of the water table in the Pampa aquifers threatening its conservation. This study aimed to determine the effect of the groundwater table depth on the water relations of P. tamarugo and to present thresholds of groundwater depth (GWD) that can be used in the groundwater management of the P. tamarugo ecosystem. Three levels of GWD, 11.2 ± 0.3 m, 10.3 ± 0.3 m, and 7.1 ± 0.1 m, (the last GWD being our reference) were selected and groups of four individuals per GWD were studied in the months of January and July of the years 2011 through 2014. When the water table depth exceeded 10 m, P. tamarugo had lower pre-dawn and mid-day water potential but no differences were observed in minimum leaf stomatal resistance when compared to the condition of 7.1 m GWD; the leaf tissue increased its δ(13)C and δ(18)O composition. Furthermore, a smaller green canopy fraction of the trees and increased foliage loss in winter with increasing water table depth was observed. The differences observed in the physiological behavior of P. tamarugo trees, attributable to the ground water depth; show that increasing the depth of the water table from 7 to 11 m significantly affects the water status of P. tamarugo. The results indicate that P. tamarugo has an anisohydric stomatal behavior and that given a reduction in water supply it regulates the water demand via foliage loss. The growth and leaf physiological activities are highly sensitive to GWD. The foliage loss appears to prevent the trees from reaching water potentials leading to complete loss of hydraulic functionality by cavitation. The balance achieved between water supply and demand was reflected in the low variation of the water potential and of the variables related to gas exchange over time for a given GWD. This acclimation capacity of P. tamarugo after

  1. Assessment of denitrification gaseous end-products in the soil profile under two water table management practices using repeated measures analysis.

    Science.gov (United States)

    Elmi, Abdirashid A; Astatkie, Tess; Madramootoo, Chandra; Gordon, Robert; Burton, David

    2005-01-01

    The denitrification process and nitrous oxide (N2O) production in the soil profile are poorly documented because most research into denitrification has concentrated on the upper soil layer (0-0.15 m). This study, undertaken during the 1999 and 2000 growing seasons, was designed to examine the effects of water table management (WTM), nitrogen (N) application rate, and depth (0.15, 0.30, and 0.45 m) on soil denitrification end-products (N2O and N2) from a corn (Zea mays L.) field. Water table management treatments were free drainage (FD) with open drains and subirrigation (SI) with a target water table depth of 0.6 m. Fertility treatments (ammonium nitrate) were 120 kg N ha(-1) (N120) and 200 kg N ha(-1) (N200). During both growing seasons greater denitrification rates were measured in SI than in FD, particularly in the surface soil (0-0.15 m) and at the intermediate (0.15-0.30 m) soil depths under N200 treatment. Greater denitrification rates under the SI treatment, however, were not accompanied with greater N2O production. The decrease in N2O production under SI was probably caused by a more complete reduction of N2O to N2, which resulted in lower N2O to (N2O + N2) ratios. Denitrification rate, N2O production and N2O to (N2O + N2) ratios were only minimally affected by N treatments, irrespective of sampling date and soil depth. Overall, half of the denitrification occurred at the 0.15- to 0.30- and 0.30- to 0.45-m soil layers, and under SI, regardless of fertility treatment level. Consequently, sampling of the 0- to 0.15-m soil layer alone may not give an accurate estimation of denitrification losses under SI practice.

  2. Nitrogen Release in Pristine and Drained Peat Profiles in Response to Water Table Fluctuations: A Mesocosm Experiment

    Directory of Open Access Journals (Sweden)

    Merjo P. P. Laine

    2013-01-01

    Full Text Available In the northern hemisphere, variability in hydrological conditions was suggested to increase as a consequence of climate warming, which may result in longer droughts than the area has experienced before. Due to their predominately anoxic conditions, peatlands are expected to respond to changes in hydrological conditions, such as successive drying and rewetting periods. As peatlands are rich in organic matter, any major changes in water table may influence the decomposition of it. The hydrological conditions may also influence release of nutrients from peat profiles as well as affect their transport to downstream ecosystems. In our mesocosm experiment, artificial water table fluctuations in pristine peat profiles caused an increase in dissolved organic nitrogen (DON and ammonium (NH4+-N concentrations, while no response was found in drained peat profiles, although originating from the same peatland complex.

  3. An analytical study on nested flow systems in a Tóthian basin with a periodically changing water table

    Science.gov (United States)

    Zhao, Ke-Yu; Jiang, Xiao-Wei; Wang, Xu-Sheng; Wan, Li; Wang, Jun-Zhi; Wang, Heng; Li, Hailong

    2018-01-01

    Classical understanding on basin-scale groundwater flow patterns is based on Tóth's findings of a single flow system in a unit basin (Tóth, 1962) and nested flow systems in a complex basin (Tóth, 1963), both of which were based on steady state models. Vandenberg (1980) extended Tóth (1962) by deriving a transient solution under a periodically changing water table in a unit basin and examined the flow field distortion under different dimensionless response time, τ∗. Following Vandenberg's (1980) approach, we extended Tóth (1963) by deriving the transient solution under a periodically changing water table in a complex basin and examined the transient behavior of nested flow systems. Due to the effect of specific storage, the flow field is asymmetric with respect to the midline, and the trajectory of internal stagnation points constitutes a non-enclosed loop, whose width decreases when τ∗ decreases. The distribution of the relative magnitude of hydraulic head fluctuation, Δh∗ , is dependent on the horizontal distance away from a divide and the depth below the land surface. In the shallow part, Δh∗ decreases from 1 at the divide to 0 at its neighboring valley under all τ∗, while in the deep part, Δh∗ reaches a threshold, whose value decreases when τ∗ increases. The zones with flowing wells are also found to change periodically. As water table falls, there is a general trend of shrinkage in the area of zones with flowing wells, which has a lag to the declining water table under a large τ∗. Although fluxes have not been assigned in our model, the recharge/discharge flux across the top boundary can be obtained. This study is critical to understand a series of periodically changing hydrogeological phenomena in large-scale basins.

  4. Quality evaluation of commercially sold table water samples in Michael Okpara University of Agriculture, Umudike, Nigeria and surrounding environments

    Directory of Open Access Journals (Sweden)

    D.O. Okorie

    2015-01-01

    Full Text Available In Michael Okpara University of Agriculture, Umudike, Nigeria (MOUAU and surrounding environments, table water of different brands is commercially hawked by vendors. To the best of our knowledge, there is no scientific documentation on the quality of these water samples. Hence this study which evaluated the quality of different brands of water samples commercially sold in MOUAU and surrounding environments. The physicochemical properties (pH, total dissolved solids (TDS, biochemical oxygen demand (BOD, total hardness, dissolved oxygen, Cl, NO3, ammonium nitrogen (NH3N, turbidity, total suspended solids (TSS, Ca, Mg, Na and K of the water samples as indices of their quality were carried out using standard techniques. Results obtained from this study indicated that most of the chemical constituents of these table water samples commercially sold in Umudike environment conformed to the standards given by the Nigerian Industrial Standard (NIS, World Health Organization (WHO and American Public Health Association (APHA, respectively, while values obtained for ammonium nitrogen in these water samples calls for serious checks on methods of their production and delivery to the end users.

  5. Manipulative lowering of the water table during summer does not affect CO2 emissions and uptake in a fen in Germany.

    Science.gov (United States)

    Muhr, Jan; Höhle, Juliane; Otieno, Dennis O; Borken, Werner

    2011-03-01

    We simulated the effect of prolonged dry summer periods by lowering the water table on three manipulation plots (D(1-3)) in a minerotrophic fen in southeastern Germany in three years (2006-2008). The water table at this site was lowered by drainage and by excluding precipitation; three nonmanipulated control plots (C(1-3)) served as a reference. We found no significant differences in soil respiration (R(Soil)), gross primary production (GPP), or aboveground respiration (R(AG)) between the C(1-3) and D(1-3) plots in any of the measurement years. The water table on the control plots was naturally low, with a median water table (2006-2008) of 8 cm below the surface, and even lower during summer when respiratory activity was highest, with median values (C(1-3)) between 11 and 19 cm below the surface. If it is assumed that oxygen availability in the uppermost 10 cm was not limited by the location of the water table, manipulative lowering of the water table most likely increased oxygen availability only in deeper peat layers where we expect R(Soil) to be limited by poor substrate quality rather than anoxia. This could explain the lack of a manipulation effect. In a second approach, we estimated the influence of the water table on R(Soil) irrespective of treatment. The results showed a significant correlation between R(Soil) and water table, but with R(Soil) decreasing at lower water tables rather than increasing. We thus conclude that decomposition in the litter layer is not limited by waterlogging in summer, and deeper peat layers bear no significant decomposition potential due to poor substrate quality. Consequently, we do not expect enhanced C losses from this site due to increasing frequency of dry summers. Assimilation and respiration of aboveground vegetation were not affected by water table fluctuations between 10 and >60 cm depth, indicating the lack of stress resulting from either anoxia (high water table) or drought (low water table).

  6. Influence of Asellus aquaticus on Escherichia coli, Klebsiella pneumoniae, Campylobacter jejuni and naturally occurring heterotrophic bacteria in drinking water

    DEFF Research Database (Denmark)

    Christensen, Sarah Christine; Nissen, Erling; Arvin, Erik

    2012-01-01

    . aquaticus on microbial water quality in non-chlorinated drinking water in controlled laboratory experiments. Pure cultures of the indicator organisms Escherichia coli and Klebsiella pneumoniae and the pathogen Campylobacter jejuni as well as naturally occurring heterotrophic drinking water bacteria...... decreased over time, following a first order decay with half lives of 5.3, 18.4 and 1.3 days, respectively. A. aquaticus did not affect survival of indicators and pathogens substantially whereas HPC were influenced by presence of dead A. aquaticus. Growth rates increased with an average of 48% for bacteria...... grown on R-2A agar and an average of 83% for bacteria grown on yeast extract agar when dead A. aquaticus were present compared to no and living A. aquaticus present. A. aquaticus associated E. coli, K. pneumoniae and C. jejuni were measured (up to 25 per living and 500 per dead A. aquaticus) and so were...

  7. Activity concentration and population dose from natural occurring radionuclide (40K) due to consumption of fresh water fish

    International Nuclear Information System (INIS)

    Jha, M.K.; Patra, A.K.; Jaison, T.J.; Ravi, P.M.; Tripathi, R.M.

    2015-01-01

    The objective of this study was to measure the concentration of natural occurring radionuclide ( 40 K) in different fresh water fish collected from Moticher lake near Kakrapar, Gujarat. The three types of commonly available fresh water fish in Moticher lake are Notopterus sps, Ophiocephalus sps. and Tor sps. The 40 K activity (Bq/kg flesh wt.) was found to be in the range of 38-100 (Notopterus sps.), 33-123 (Ophiocephalus sps.) and 80-116 (Tor sps.) respectively. The ingestion dose (μSv/y) to the adult population around Kakrapar was estimated due to the consumption of fresh water fish and found to be in the range of 7.7-20.5 (Notopterus sps.), 6.8-25.0 (Ophiocephalus sps.) and 16.0-24.0 (Tor sps.) respectively. (author)

  8. Culture of microalgae biomass for valorization of table olive processing water

    Directory of Open Access Journals (Sweden)

    Contreras, C. G.

    2016-09-01

    Full Text Available Table olive processing water (TOPW contains many complex substances, such as phenols, which could be valorized as a substrate for microalgae biomass culture. The aim of this study was to assess the capability of Nannochloropsis gaditana to grow in TOPW at different concentrations (10- 80% in order to valorize this processing water. Within this range, the highest increment of biomass was determined at percentage of 40% of TOPW, reaching an increment of 0.36 ± 0.05 mg volatile suspended solids (VSS/L. Components of algal biomass were similar for the experiments at 10-40% of TOPW, where proteins were the major compounds (56-74%. Total phenols were retained in the microalgae biomass (0.020 ± 0.002 g of total phenols/g VSS. Experiments for 80% of TOPW resulted in a low production of microalgae biomass. High organic matter, nitrogen, phosphorus and phenol removal were achieved in all TOPW concentrations. Although high-value products, such as proteins, were obtained and high removal efficiencies of nutrients were determined, microalgae biomass culture should be enhanced to become a suitable integral processing water treatment.El agua resultante del proceso de elaboración de la aceituna de mesa (TOPW presenta un elevado contenido en sustancias complejas, como fenoles, que podría permitir su uso como sustrato para el cultivo de microalgas. El objetivo de este estudio se centra en evaluar la capacidad de crecimiento de Nannochloropsis gaditana en TOPW a distintas concentraciones (10-80% con vistas a la valorización de estas aguas. El mayor incremento de biomasa se obtuvo para un porcentaje del 40% de TOPW, alcanzando un aumento de 0.36 ± 0.50 mg sólidos en suspensión volátiles (SSV/L. Los componentes presentes en la biomasa han sido similares para los experimentos con 10-40% de TOPW, siendo las proteínas los compuestos mayoritarios en todos los casos (56-74%. Los fenoles totales quedaron retenidos en las microalgas, alcanzando una concentraci

  9. Tables of homogeneous equilibrium critical flow parameters for water in SI units

    International Nuclear Information System (INIS)

    Hall, D.G.; Czapary, L.S.

    1980-09-01

    This reference document presents tables and charts containing data calculated using the homogeneous equilibrium critical flow model (HEM). The ranges of stagnation state properties for which data are presented include: pressures from 2 to 22 120kPa, temperatures from 290 to 640 K, and thermodynamic qualities from 0 to 1

  10. A Mathematical View of Water Table Fluctuations in a Shallow Aquifer in Brazil

    NARCIS (Netherlands)

    Neto, Dagmar C.; Chang, Hung K.; van Genuchten, Martinus Th

    Detailed monitoring of the groundwater table can provide important data about both short- and long-term aquifer processes, including information useful for estimating recharge and facilitating groundwater modeling and remediation efforts. In this paper, we presents results of 4years (2002 to 2005)

  11. Use of well points to determine the thickness and extent of floating product atop the water table

    International Nuclear Information System (INIS)

    Liikala, T.L.; Lewis, R.; Gilmore, T.; Hoffmann, H.

    1994-01-01

    The release of petroleum products to the ground water is a widespread problem. Conventional plume tracking techniques are to drill wells and measure product thickness and extent. In this study, well points were installed to rapidly and inexpensively determine the thickness and extent of floating product atop the water table. Spills and leaks of JP-4 have produced a discrete full layer atop the water table at one site at Eielson Air Force Base near Fairbanks, Alaska. The 0.2- to 1.3-foot-thick layer was identified in two ground water monitoring wells at a depth of approximately 10 feet. The layer is contained within unconsolidated glaciofluvial sands and gravels. A comprehensive assessment of the product thickness and extent was necessary for the site remedial investigation/feasibility study. The emplacement of additional monitoring wells was discouraged because of time and budget constraints. The fuel layer was delineated with 18 screened well points. The points consist of 2-inch-diameter galvanized steel pipe. The points were driven into the floating products with a hollow-stem auger rig sampling hammer. The product thickness was measured with an interface probe. The presence of floating product could be measured immediately after emplacement; the product thickness measurements typically stabilized within three days. The product thickness compared favorably with those measured in adjacent monitoring wells

  12. The effect of urbanization in an arid region: Formation of a perched water table that causes environmental damages

    Science.gov (United States)

    Karnieli, A.; Issar, A.; Wolf, M.

    1984-03-01

    Construction in a new neighborhood in the israeli town of Dimona, situated in an arid region in the south of the country (150 mm average annual rainfall), resulted in a rise in groundwater levels during the subsequent rainy seasons This caused flooding of shelter basements, soil sliding, and sagging which permanently damaged walls and buildings The neighborhood had been built on continental sands and marls blanketed by loess, on a valley slope near a rocky anticlinal dip-slope Subsurface studies, using piezometer holes and groundwater analyses, revealed the presence of sand lenses alternating with plastic marls, which act as seasonal aquifers with perched water tables Groundwaters obtain high SO{4/-2} and Cl- corrosivity through contact with these nonflushed marls of the Neogene valley fill (Hazeva Formation) The reasons for the rising of groundwater were found to be (a) artificial interference with the natural (pre-construction) drainage system—interception of the hillside runoff by building plots, roads, etc, (b) partial denudation of the loess blanket, increasing the local infiltration and the build-up of local, perched water tables, and (c) corrosion of concrete and steel pipelines, as well as foundations, by prolonged contact with corrosive groundwater, resulting in haphazard but massive leakage Guidelines are proposed for an environmental improvement plan, which would include terracing and planting of the watershed above town to increase evapotranspiration, lowering of the water table by pumping, and diverting the water to suburban parks (groves of saltresistant trees), and replacement of steel and cement pipes by a non-corrodable plastic pipe system

  13. Comparison of thermally induced and naturally occurring water-borne leakages from hard rock depositories for radioactive waste

    International Nuclear Information System (INIS)

    Bourke, P.J.; Robinson, P.C.

    1981-01-01

    The relative importance of thermally induced and naturally occurring flows of water as causes of leakage from hard rock depositories for radioactive wastes is assessed. Separate analyses are presented for involatile, high level waste from reprocessing of fuel and for plutonium contaminated waste from fabrication of fuel. The effects of varying the quantities of wastes, pre-burial storage and the shapes and depths of depositories are considered. It is concluded that for representative values of these variables, thermal flow will remain the major cause of leakage for long times after the burial of both types of waste. (Auth.)

  14. Estimation of groundwater consumption by phreatophytes using diurnal water table fluctuations: A saturated‐unsaturated flow assessment

    Science.gov (United States)

    Loheide, Steven P.; Butler, James J.; Gorelick, Steven M.

    2005-01-01

    Groundwater consumption by phreatophytes is a difficult‐to‐measure but important component of the water budget in many arid and semiarid environments. Over the past 70 years the consumptive use of groundwater by phreatophytes has been estimated using a method that analyzes diurnal trends in hydrographs from wells that are screened across the water table (White, 1932). The reliability of estimates obtained with this approach has never been rigorously evaluated using saturated‐unsaturated flow simulation. We present such an evaluation for common flow geometries and a range of hydraulic properties. Results indicate that the major source of error in the White method is the uncertainty in the estimate of specific yield. Evapotranspirative consumption of groundwater will often be significantly overpredicted with the White method if the effects of drainage time and the depth to the water table on specific yield are ignored. We utilize the concept of readily available specific yield as the basis for estimation of the specific yield value appropriate for use with the White method. Guidelines are defined for estimating readily available specific yield based on sediment texture. Use of these guidelines with the White method should enable the evapotranspirative consumption of groundwater to be more accurately quantified.

  15. Preliminary phenomena identification and ranking tables for simplified boiling water reactor Loss-of-Coolant Accident scenarios

    International Nuclear Information System (INIS)

    Kroeger, P.G.; Rohatgi, U.S.; Jo, J.H.; Slovik, G.C.

    1998-04-01

    For three potential Loss-of-Coolant Accident (LOCA) scenarios in the General Electric Simplified Boiling Water Reactors (SBWR) a set of Phenomena Identification and Ranking Tables (PIRT) is presented. The selected LOCA scenarios are typical for the class of small and large breaks generally considered in Safety Analysis Reports. The method used to develop the PIRTs is described. Following is a discussion of the transient scenarios, the PIRTs are presented and discussed in detailed and in summarized form. A procedure for future validation of the PIRTs, to enhance their value, is outlined. 26 refs., 25 figs., 44 tabs

  16. Estimating the water table under the Radioactive Waste Management Site in Area 5 of the Nevada Test Site: The Dupuit-Forcheimer approximation

    International Nuclear Information System (INIS)

    Lindstrom, F.T.; Barker, L.E.; Cawlfield, D.E.; Daffern, D.D.; Dozier, B.L.; Emer, D.F.; Strong, W.R.

    1992-01-01

    To adequately manage the low level nuclear waste (LLW) repository in Area 5 of the Nevada Test Site (NTS), a knowledge of the water table under the site is paramount. The estimated thickness of the arid intermountain basin alluvium is roughly 900 feet. Very little reliable water table data for Area 5 currently exists. The Special Projects Section of the Reynolds Electrical ampersand Engineering Co., Inc. Waste Management Department is currently formulating a long-range drilling and sampling plan in support of a Resource Conservation Recovery Act (RCRA) Part B permit waiver for groundwater monitoring and liner systems. An estimate of the water table under the LLW repository, called the Radioactive Waste Management Site (RWMS) in Area 5, is needed for the drilling and sampling plan. Very old water table elevation estimates at about a dozen widely scattered test drill holes, as well as water wells, are available from declassified US Geological Survey, Lawrence Livermore National Laboratory, and Los Alamos National Laboratory drilling logs. A three-dimensional steady-state water-flow equation for estimating the water table elevation under a thick, very dry vadose zone is developed using the Dupuit assumption. A prescribed positive vertical downward infiltration/evaporation condition is assumed at the atmosphere/soil interface. An approximation to the square of the elevation head, based upon multivariate cubic interpolation methods, is introduced. The approximate is forced to satisfy the governing elliptic (Poisson) partial differential equation over the domain of definition. The remaining coefficients are determined by interpolating the water table at eight ''boundary point.'' Several realistic scenarios approximating the water table under the RWMS in Area 5 of the NTS are discussed

  17. Paleohydrology of the southern Great Basin, with special reference to water table fluctuations beneath the Nevada Test Site during the late(?) Pleistocene

    Science.gov (United States)

    Winograd, Isaac Judah; Doty, Gene C.

    1980-01-01

    Knowledge of the magnitude of water-table rise during Pleistocene pluvial climates, and of the resultant shortening of groundwater flow path and reduction in unsaturated zone thickness, is mandatory for a technical evaluation of the Nevada Test Site (NTS) or other arid zone sites as repositories for high-level or transuranic radioactive wastes. The distribution of calcitic veins filling fractures in alluvium, and of tufa deposits between the Ash Meadows spring discharge area and the Nevada Test Site indicates that discharge from the regional Paleozoic carbonate aquifer during the Late( ) Pleistocene pluvial periods may have occurred at an altitude about 50 meters higher than at present and 14 kilometers northeast of Ash Meadows. Use of the underflow equation (relating discharge to transmissivity, aquifer width, and hydraulic gradient), and various assumptions regarding pluvial recharge, transmissivity, and altitude of groundwater base level, suggest possible rises in potentiometric level in the carbonate aquifer of about -90 meters beneath central Frenchman Flat. During Wisconsin time the rise probably did not exceed 30 meters. Water-level rises beneath Frenchman Flat during future pluvials are unlikely to exceed 30 meters and might even be 10 meters lower than modern levels. Neither the cited rise in potentiometric level in the regional carbonate aquifer, nor the shortened flow path during the Late( ) Pleistocene preclude utilization of the NTS as a repository for high-level or transuranic-element radioactive wastes provided other requisite conditions are met as this site. Deep water tables, attendant thick (up to several hundred meter) unsaturated zones, and long groundwater flow paths characterized the region during the Wisconsin Stage and probably throughout the Pleistocene Epoch and are likely to so characterize it during future glacial periods. (USGS)

  18. APPLICATION OF THE NATURALLY-OCCURRING DEUTERIUM ISOTOPE TO TRACING THE CAPILLARY FRINGE

    Science.gov (United States)

    Naturally-occurring deuterium is a useful tracer of subsurface hydrologic processes. A possible application includes the identification of capillary fringes in the vadose zone. Multiple and discontinuous water tables persist in many temperate regions, under various hydrogeologi...

  19. Groundwater in the Boreal Plains: How Climate and Geology Interact to Control Water Table Configurations in a Sub-Humid, Low-Relief Region

    Science.gov (United States)

    Hokanson, K. J.; Devito, K.; Mendoza, C. A.

    2017-12-01

    The Boreal Plain (BP) region of Canada, a landscape characterized by low-relief, a sub-humid climate and heterogeneous glacial landforms, is experiencing unprecedented anthropogenic and natural disturbance, including climate change and oil & gas operations. Understanding the controls on and the natural variability of water table position, and subsequently predicting changes in water table position under varying physical and climatic scenarios will become important as water security becomes increasingly threatened. The BP is composed of a mosaic of forestland, wetland, and aquatic land covers that contrast in dominant vegetation cover, evapotranspiration, and soil storage that, in turn, influence water table configurations. Additionally, these land-covers overlie heterogeneous glacial landforms with large contrasts in storage and hydraulic properties which, when coupled with wet-dry climate cycles, result in complex water table distributions in time and space. Several forestland-wetland-pond complexes were selected at the Utikuma Research Study Area (URSA) over three distinct surficial geologic materials (glacial fluvial outwash, stagnant ice moraine, lacustrine clay plain) to explore the roles of climate (cumulative departure from the long term yearly mean precipitation), geology, topographic position, and land cover on water table configurations over 15 years (2002 - 2016). In the absence of large groundwater flow systems, local relief and shallow low conductivity substrates promote the formation of near-surface water tables that are less susceptible to climate variation, regardless of topography. Furthermore, in areas of increased storage, wet and dry climate conditions can result in appreciably different water table configurations over time, ranging from mounds to hydraulic depressions, depending on the arrangement of land-covers, dominant surficial geology, and substrate layering.

  20. Rapid response of hydrological loss of DOC to water table drawdown and warming in Zoige peatland: results from a mesocosm experiment.

    Science.gov (United States)

    Lou, Xue-Dong; Zhai, Sheng-Qiang; Kang, Bing; Hu, Ya-Lin; Hu, Li-Le

    2014-01-01

    A large portion of the global carbon pool is stored in peatlands, which are sensitive to a changing environment conditions. The hydrological loss of dissolved organic carbon (DOC) is believed to play a key role in determining the carbon balance in peatlands. Zoige peatland, the largest peat store in China, is experiencing climatic warming and drying as well as experiencing severe artificial drainage. Using a fully crossed factorial design, we experimentally manipulated temperature and controlled the water tables in large mesocosms containing intact peat monoliths. Specifically, we determined the impact of warming and water table position on the hydrological loss of DOC, the exported amounts, concentrations and qualities of DOC, and the discharge volume in Zoige peatland. Our results revealed that of the water table position had a greater impact on DOC export than the warming treatment, which showed no interactive effects with the water table treatment. Both DOC concentration and discharge volume were significantly increased when water table drawdown, while only the DOC concentration was significantly promoted by warming treatment. Annual DOC export was increased by 69% and 102% when the water table, controlled at 0 cm, was experimentally lowered by -10 cm and -20 cm. Increases in colored and aromatic constituents of DOC (measured by Abs(254 nm), SUVA(254 nm), Abs(400 nm), and SUVA(400 nm)) were observed under the lower water tables and at the higher peat temperature. Our results provide an indication of the potential impacts of climatic change and anthropogenic drainage on the carbon cycle and/or water storage in a peatland and simultaneously imply the likelihood of potential damage to downstream ecosystems. Furthermore, our results highlight the need for local protection and sustainable development, as well as suggest that more research is required to better understand the impacts of climatic change and artificial disturbances on peatland degradation.

  1. Rapid response of hydrological loss of DOC to water table drawdown and warming in Zoige peatland: results from a mesocosm experiment.

    Directory of Open Access Journals (Sweden)

    Xue-Dong Lou

    Full Text Available A large portion of the global carbon pool is stored in peatlands, which are sensitive to a changing environment conditions. The hydrological loss of dissolved organic carbon (DOC is believed to play a key role in determining the carbon balance in peatlands. Zoige peatland, the largest peat store in China, is experiencing climatic warming and drying as well as experiencing severe artificial drainage. Using a fully crossed factorial design, we experimentally manipulated temperature and controlled the water tables in large mesocosms containing intact peat monoliths. Specifically, we determined the impact of warming and water table position on the hydrological loss of DOC, the exported amounts, concentrations and qualities of DOC, and the discharge volume in Zoige peatland. Our results revealed that of the water table position had a greater impact on DOC export than the warming treatment, which showed no interactive effects with the water table treatment. Both DOC concentration and discharge volume were significantly increased when water table drawdown, while only the DOC concentration was significantly promoted by warming treatment. Annual DOC export was increased by 69% and 102% when the water table, controlled at 0 cm, was experimentally lowered by -10 cm and -20 cm. Increases in colored and aromatic constituents of DOC (measured by Abs(254 nm, SUVA(254 nm, Abs(400 nm, and SUVA(400 nm were observed under the lower water tables and at the higher peat temperature. Our results provide an indication of the potential impacts of climatic change and anthropogenic drainage on the carbon cycle and/or water storage in a peatland and simultaneously imply the likelihood of potential damage to downstream ecosystems. Furthermore, our results highlight the need for local protection and sustainable development, as well as suggest that more research is required to better understand the impacts of climatic change and artificial disturbances on peatland degradation.

  2. Determination of distribution coefficient (Kd's) of some artificial and naturally occurring radionuclide in fresh and marine coastal water sediment

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Mamish, S; Haleem, M. A.

    2004-12-01

    Distribution coefficients of artificial and natural radionuclides in fresh and marine water sediment are used in modeling radionuclide dispersion in water system, and the radiation risk and environmental investigating of impact of radioactive emissions, due to routine operations of nuclear plants or disposal and burial of radioactive waste in the environment. In the present work, distribution coefficient of uranium, lead, polonium, radium (naturally occurring radionuclides that may be emitted into the Syrian environment by the phosphate and oil industry with relatively high concentrations) and caesium 137 and strontium 85, in fresh water sediment (Euphrates River, Orantos River and Mzzerib Lake) and marine coastal water (Lattakia, Tartous and Banias). Distribution coefficients were found to vary between (5.8-17.18)*10 3 , (2.2-8.11)*10 3 , (0.22-2.08)*10 3 , (0.16-0.19)*10 3 , (0.38-0.69)*10 3 and 49-312 for polonium, lead, uranium, radium, cesium and strontium respectively. Results have indicated that most measurement distribution coefficients in the present study were lower than those values reported in IAEA documents for marine coastal sediment. In addition, variations of Kd's with aqueous phase composition and sediment elemental and mineralogical composition and its total organic materials content have been studied, where liner correlation coefficients for each isotope with different parameters have been determined. The obtained data reported in this study can be used for radioactive contaminants dispersion and transfer in Syrian river, lake and coast to assess risks to public due to discharges of the phosphate and oil industry into the Syrian environment. (Authors)

  3. Shallow water table effects on water, sediment, and pesticide transport in vegetative filter strips - Part 1: nonuniform infiltration and soil water redistribution

    Science.gov (United States)

    Muñoz-Carpena, Rafael; Lauvernet, Claire; Carluer, Nadia

    2018-01-01

    Vegetation buffers like vegetative filter strips (VFSs) are often used to protect water bodies from surface runoff pollution from disturbed areas. Their typical placement in floodplains often results in the presence of a seasonal shallow water table (WT) that can decrease soil infiltration and increase surface pollutant transport during a rainfall-runoff event. Simple and robust components of hydrological models are needed to analyze the impacts of WT in the landscape. To simulate VFS infiltration under realistic rainfall conditions with WT, we propose a generic infiltration solution (Shallow Water table INfiltration algorithm: SWINGO) based on a combination of approaches by Salvucci and Entekhabi (1995) and Chu (1997) with new integral formulae to calculate singular times (time of ponding, shift time, and time to soil profile saturation). The algorithm was tested successfully on five distinct soils, both against Richards's numerical solution and experimental data in terms of infiltration and soil moisture redistribution predictions, and applied to study the combined effects of varying WT depth, soil type, and rainfall intensity and duration. The results show the robustness of the algorithm and its ability to handle various soil hydraulic functions and initial nonponding conditions under unsteady rainfall. The effect of a WT on infiltration under ponded conditions was found to be effectively decoupled from surface infiltration and excess runoff processes for depths larger than 1.2 to 2 m, being shallower for fine soils and shorter events. For nonponded initial conditions, the influence of WT depth also varies with rainfall intensity. Also, we observed that soils with a marked air entry (bubbling pressure) exhibit a distinct behavior with WT near the surface. The good performance, robustness, and flexibility of SWINGO supports its broader use to study WT effects on surface runoff, infiltration, flooding, transport, ecological, and land use processes. SWINGO is

  4. Shallow water table effects on water, sediment, and pesticide transport in vegetative filter strips – Part 1: nonuniform infiltration and soil water redistribution

    Directory of Open Access Journals (Sweden)

    R. Muñoz-Carpena

    2018-01-01

    Full Text Available Vegetation buffers like vegetative filter strips (VFSs are often used to protect water bodies from surface runoff pollution from disturbed areas. Their typical placement in floodplains often results in the presence of a seasonal shallow water table (WT that can decrease soil infiltration and increase surface pollutant transport during a rainfall-runoff event. Simple and robust components of hydrological models are needed to analyze the impacts of WT in the landscape. To simulate VFS infiltration under realistic rainfall conditions with WT, we propose a generic infiltration solution (Shallow Water table INfiltration algorithm: SWINGO based on a combination of approaches by Salvucci and Entekhabi (1995 and Chu (1997 with new integral formulae to calculate singular times (time of ponding, shift time, and time to soil profile saturation. The algorithm was tested successfully on five distinct soils, both against Richards's numerical solution and experimental data in terms of infiltration and soil moisture redistribution predictions, and applied to study the combined effects of varying WT depth, soil type, and rainfall intensity and duration. The results show the robustness of the algorithm and its ability to handle various soil hydraulic functions and initial nonponding conditions under unsteady rainfall. The effect of a WT on infiltration under ponded conditions was found to be effectively decoupled from surface infiltration and excess runoff processes for depths larger than 1.2 to 2 m, being shallower for fine soils and shorter events. For nonponded initial conditions, the influence of WT depth also varies with rainfall intensity. Also, we observed that soils with a marked air entry (bubbling pressure exhibit a distinct behavior with WT near the surface. The good performance, robustness, and flexibility of SWINGO supports its broader use to study WT effects on surface runoff, infiltration, flooding, transport, ecological, and land use processes

  5. Spatial variation of nitrogen pollution of the water table at Oued M'Zab (Northern Algerian Sahara)

    Science.gov (United States)

    Benhedid, H.; Bouhoun, M. Daddi

    2018-05-01

    The aim of our work is the study of spatial variations of the water table pollution of Oued M'Zab, in order to determine their abilities of use and the posed problems of degradation. The methodological approach we adopted is to make a spatial study of the variability of nitrogen pollution, as well as to classify water quality according to international standards. The main results obtained in this research show that NH4+ range from 0 to 0,143 mg.l-1 with an average of 0,048 ± 0,039 mg.l-1, the NO2- from 0 to 0,209 mg.l-1 give an average of 0,007 ± 0,033 mg.l-1, and the NO3- vary between 14,264 and 143,465 mg.l-1, with a mean value 54,594 ± 30,503 mg.l-1. According to W.H.O. standards, the majority of these waters are classified as polluted and not drinkable. Our research shows a degradation of the underground water resources in M'Zab Valley. It resulted that it is essential to regulate the use of water and set out other adjustments in order to safeguard the underground water resources so as to promote sustainable development in the valley of M'Zab.

  6. Effect of vegetation removal and water table drawdown on the non-methane biogenic volatile organic compound emissions in boreal peatland microcosms

    Science.gov (United States)

    Faubert, Patrick; Tiiva, Päivi; Rinnan, Åsmund; Räty, Sanna; Holopainen, Jarmo K.; Holopainen, Toini; Rinnan, Riikka

    2010-11-01

    Biogenic volatile organic compound (BVOC) emissions are important in the global atmospheric chemistry and their feedbacks to global warming are uncertain. Global warming is expected to trigger vegetation changes and water table drawdown in boreal peatlands, such changes have only been investigated on isoprene emission but never on other BVOCs. We aimed at distinguishing the BVOCs released from vascular plants, mosses and peat in hummocks (dry microsites) and hollows (wet microsites) of boreal peatland microcosms maintained in growth chambers. We also assessed the effect of water table drawdown (-20 cm) on the BVOC emissions in hollow microcosms. BVOC emissions were measured from peat samples underneath the moss surface after the 7-week-long experiment to investigate whether the potential effects of vegetation and water table drawdown were shown. BVOCs were sampled using a conventional chamber method, collected on adsorbent and analyzed with GC-MS. In hummock microcosms, vascular plants increased the monoterpene emissions compared with the treatment where all above-ground vegetation was removed while no effect was detected on the sesquiterpenes, other reactive VOCs (ORVOCs) and other VOCs. Peat layer from underneath the surface with intact vegetation had the highest sesquiterpene emissions. In hollow microcosms, intact vegetation had the highest sesquiterpene emissions. Water table drawdown decreased monoterpene and other VOC emissions. Specific compounds could be closely associated to the natural/lowered water tables. Peat layer from underneath the surface of hollows with intact vegetation had the highest emissions of monoterpenes, sesquiterpenes and ORVOCs whereas water table drawdown decreased those emissions. The results suggest that global warming would change the BVOC emission mixtures from boreal peatlands following changes in vegetation composition and water table drawdown.

  7. Effects of Drought on Xylem Anatomy and Water-Use Efficiency of Two Co-Occurring Pine Species

    Directory of Open Access Journals (Sweden)

    Dario Martin-Benito

    2017-09-01

    Full Text Available Exploring how drought influences growth, performance, and survival in different species is crucial to understanding the impacts of climate change on forest ecosystems. Here, we investigate the responses of two co-occurring pines (Pinus nigra and Pinus sylvestris to interannual drought in east-central Spain by dendrochronological and wood anatomical features integrated with isotopic ratios of carbon (δ13C and oxygen (δ18O in tree rings. Our results showed that drought induces both species to allocate less carbon to build tracheid cell-walls but increases tracheid lumen diameters, particularly in the transition wood between early and latewood, potentially maximizing hydraulic conductivity but reducing resistance to embolism at a critical phase during the growing season. The thicker cell-wall-to-lumen ratio in P. nigra could imply that its xylem may be more resistant to bending stress and drought-induced cavitation than P. sylvestris. In contrast, the higher intrinsic water-use efficiency (iWUE in P. sylvestris suggests that it relies more on a water-saving strategy. Our results suggest that narrower cell-walls and reduced growth under drought are not necessarily linked to increased iWUE. At our site P. nigra showed a higher growth plasticity, grew faster and was more competitive than P. sylvestris. In the long term, these sustained differences in iWUE and anatomical characters could affect forest species performance and composition, particularly under increased drought stress.

  8. Estimation of bare soil evaporation for different depths of water table in the wind-blown sand area of the Ordos Basin, China

    Science.gov (United States)

    Chen, Li; Wang, Wenke; Zhang, Zaiyong; Wang, Zhoufeng; Wang, Qiangmin; Zhao, Ming; Gong, Chengcheng

    2018-04-01

    Soil surface evaporation is a significant component of the hydrological cycle, occurring at the interface between the atmosphere and vadose zone, but it is affected by factors such as groundwater level, soil properties, solar radiation and others. In order to understand the soil evaporation characteristics in arid regions, a field experiment was conducted in the Ordos Basin, central China, and high accuracy sensors of soil moisture, moisture potential and temperature were installed in three field soil profiles with water-table depths (WTDs) of about 0.4, 1.4 and 2.2 m. Soil-surface-evaporation values were estimated by observed data combined with Darcy's law. Results showed that: (1) soil-surface-evaporation rate is linked to moisture content and it is also affected by air temperature. When there is sufficient moisture in the soil profile, soil evaporation increases with rising air temperature. For a WTD larger than the height of capillary rise, the soil evaporation is related to soil moisture content, and when air temperature is above 25 °C, the soil moisture content reduces quickly and the evaporation rate lowers; (2) phreatic water contributes to soil surface evaporation under conditions in which the WTD is within the capillary fringe. This indicates that phreatic water would not participate in soil evaporation for a WTD larger than the height of capillary rise. This finding developed further the understanding of phreatic evaporation, and this study provides valuable information on recognized soil evaporation processes in the arid environment.

  9. Role of co-occurring competition and facilitation in plant spacing hydrodynamics in water-limited environments

    Science.gov (United States)

    2017-01-01

    Plant performance (i.e., fecundity, growth, survival) depends on an individual’s access to space and resources. At the community level, plant performance is reflected in observable vegetation patterning (i.e., spacing distance, density) often controlled by limiting resources. Resource availability is, in turn, strongly dependent on plant patterning mediated by competitive and facilitative plant–plant interactions. Co-occurring competition and facilitation has never been specifically investigated from a hydrodynamic perspective. To address this knowledge gap, and to overcome limitations of field studies, three intermediate-scale laboratory experiments were conducted using a climate-controlled wind tunnel–porous media test facility to simulate the soil–plant–atmosphere continuum. The spacing between two synthetic plants, a design consideration introduced by the authors in a recent publication, was varied between experiments; edaphic and mean atmospheric conditions were held constant. The strength of the above- and belowground plant–plant interactions changed with spacing distance, allowing the creation of a hydrodynamic conceptual model based on established ecological theories. Greatest soil water loss was observed for the experiment with the smallest spacing where competition dominated. Facilitation dominated at the intermediate spacing; little to no interactions were observed for the largest plant spacing. Results suggest that there exists an optimal spacing distance range that lowers plant environmental stress, thus improving plant performance through reduced atmospheric demand and conservation of available soil water. These findings may provide a foundation for improving our understanding of many climatological, ecohydrological, and hydrological problems pertaining to the hydrodynamics of water-limited environments where plant–plant interactions and community self-organization are important. PMID:28807999

  10. Shallow water table effects on water, sediment, and pesticide transport in vegetative filter strips - Part 2: model coupling, application, factor importance, and uncertainty

    Science.gov (United States)

    Lauvernet, Claire; Muñoz-Carpena, Rafael

    2018-01-01

    Vegetative filter strips are often used for protecting surface waters from pollution transferred by surface runoff in agricultural watersheds. In Europe, they are often prescribed along the stream banks, where a seasonal shallow water table (WT) could decrease the buffer zone efficiency. In spite of this potentially important effect, there are no systematic experimental or theoretical studies on the effect of this soil boundary condition on the VFS efficiency. In the companion paper (Muñoz-Carpena et al., 2018), we developed a physically based numerical algorithm (SWINGO) that allows the representation of soil infiltration with a shallow water table. Here we present the dynamic coupling of SWINGO with VFSMOD, an overland flow and transport mathematical model to study the WT influence on VFS efficiency in terms of reductions of overland flow, sediment, and pesticide transport. This new version of VFSMOD was applied to two contrasted benchmark field studies in France (sandy-loam soil in a Mediterranean semicontinental climate, and silty clay in a temperate oceanic climate), where limited testing of the model with field data on one of the sites showed promising results. The application showed that for the conditions of the studies, VFS efficiency decreases markedly when the water table is 0 to 1.5 m from the surface. In order to evaluate the relative importance of WT among other input factors controlling VFS efficiency, global sensitivity and uncertainty analysis (GSA) was applied on the benchmark studies. The most important factors found for VFS overland flow reduction were saturated hydraulic conductivity and WT depth, added to sediment characteristics and VFS dimensions for sediment and pesticide reductions. The relative importance of WT varied as a function of soil type (most important at the silty-clay soil) and hydraulic loading (rainfall + incoming runoff) at each site. The presence of WT introduced more complex responses dominated by strong interactions in

  11. Shallow water table effects on water, sediment, and pesticide transport in vegetative filter strips – Part 2: model coupling, application, factor importance, and uncertainty

    Directory of Open Access Journals (Sweden)

    C. Lauvernet

    2018-01-01

    Full Text Available Vegetative filter strips are often used for protecting surface waters from pollution transferred by surface runoff in agricultural watersheds. In Europe, they are often prescribed along the stream banks, where a seasonal shallow water table (WT could decrease the buffer zone efficiency. In spite of this potentially important effect, there are no systematic experimental or theoretical studies on the effect of this soil boundary condition on the VFS efficiency. In the companion paper (Muñoz-Carpena et al., 2018, we developed a physically based numerical algorithm (SWINGO that allows the representation of soil infiltration with a shallow water table. Here we present the dynamic coupling of SWINGO with VFSMOD, an overland flow and transport mathematical model to study the WT influence on VFS efficiency in terms of reductions of overland flow, sediment, and pesticide transport. This new version of VFSMOD was applied to two contrasted benchmark field studies in France (sandy-loam soil in a Mediterranean semicontinental climate, and silty clay in a temperate oceanic climate, where limited testing of the model with field data on one of the sites showed promising results. The application showed that for the conditions of the studies, VFS efficiency decreases markedly when the water table is 0 to 1.5 m from the surface. In order to evaluate the relative importance of WT among other input factors controlling VFS efficiency, global sensitivity and uncertainty analysis (GSA was applied on the benchmark studies. The most important factors found for VFS overland flow reduction were saturated hydraulic conductivity and WT depth, added to sediment characteristics and VFS dimensions for sediment and pesticide reductions. The relative importance of WT varied as a function of soil type (most important at the silty-clay soil and hydraulic loading (rainfall + incoming runoff at each site. The presence of WT introduced more complex responses dominated by strong

  12. Estimating the water table under the Radioactive Waste Management Site in Area 5 of the Nevada Test Site the Dupuit-Forcheimer approximation

    International Nuclear Information System (INIS)

    Lindstrom, T.F.; Barker, L.E.; Cawlfield, D.E.; Daffern, D.D.; Dozier, B.L.; Emer, D.F.; Strong, W.R.

    1992-01-01

    A two-dimensional steady-state water-flow equation for estimating the water table elevation under a thick, very dry vadose zone is developed and discussed. The Dupuit assumption is made. A prescribed downward vertical infiltration/evaporation condition is assumed at the atmosphere-soil interface. An approximation to the square of the elevation head, based upon multivariate cubic interpolation methods, is introduced. The approximation is forced to satisfy the governing elliptic (Poisson) partial differential equation over the domain of definition. The remaining coefficients are determined by interpolating the water table at eight ''boundary points.'' Several realistic scenarios approximating the water table under the Radioactive Waste Management Site (RWMS) in Area 5 of the Nevada Test Site (NTS) are discussed

  13. Evaporation from bare ground with different water-table depths based on an in-situ experiment in Ordos Plateau, China

    Science.gov (United States)

    Zhang, Zaiyong; Wang, Wenke; Wang, Zhoufeng; Chen, Li; Gong, Chengcheng

    2018-03-01

    The dynamic processes of ground evaporation are complex and are related to a multitude of factors such as meteorological influences, water-table depth, and materials in the unsaturated zone. To investigate ground evaporation from a homogeneous unsaturated zone, an in-situ experiment was conducted in Ordos Plateau of China. Two water-table depths were chosen to explore the water movement in the unsaturated zone and ground evaporation. Based on the experimental and calculated results, it was revealed that (1) bare ground evaporation is an atmospheric-limited stage for the case of water-table depth being close to the capillary height; (2) the bare ground evaporation is a water-storage-limited stage for the case of water-table depth being beyond the capillary height; (3) groundwater has little effect on ground-surface evaporation when the water depth is larger than the capillary height; and (4) ground evaporation is greater at nighttime than that during the daytime; and (5) a liquid-vapor interaction zone at nearly 20 cm depth is found, in which there exists a downward vapor flux on sunny days, leading to an increasing trend of soil moisture between 09:00 to 17:00; the maximum value is reached at midday. The results of this investigation are useful to further understand the dynamic processes of ground evaporation in arid areas.

  14. Effect of agroforestry system on yield attributes of wheat (Triticum Aestivum l.) under shallow water table conditions

    International Nuclear Information System (INIS)

    Kiran, R.; Agnihotri, A.K.

    2001-01-01

    Fifteen tree rows of Eucalyptus tereticornis were planted at G.B.Pant University of Agriculture and Technology, Pant Nagar, located in tarai region of Uttaranchal in a Nelder fan design in March 1989 at the angle of 24øN' from each other starting from north in anticlockwise direction. Area per tree was 30 m 2 . Wheat was intercropped with Eucalyptus tereticornis of 21st November, 1996. Each row of trees was one treatment. There were 15 treatments with control as sole crop. Various yield attributes, net radiation and water table depth were measured below trees and in control, simultaneously. In treatments 7, 8, 9, 10 and 12 early vegetative growth was observed below trees. Higher yield attributing characters were also observed in some of the treatments below trees. In general, treatment 9 (192-216ø) gave better yield attributes than that of control

  15. Creation of Soil Water and Physical data base and its inclusion in a new version of GIS of Soil Resources Attributive Table

    International Nuclear Information System (INIS)

    Kolev, Boyko

    2013-01-01

    For better using of GIS of Soil Resources a new version of the attributive table formation was created. This makes possible soil, physical, and water properties to be included into the table. The simulation procedure for soil hydro-physical properties determination was realized by using the soil particle size distribution data only. This develops a calculation algorithm for soil water content dynamic monitoring, which was realized for some of Bulgarian soils. The main aims of the study are: To demonstrate the usefulness of the new version of the attributive table formation. To show how the simulation model can be applied for environment conditions monitoring and agricultural production management. Keywords: environment conditions, simulation model, soil moisture at field capacity, wilting point, effective soil water content, particle size distribution

  16. Drought occurence

    Science.gov (United States)

    John W. Coulston

    2007-01-01

    Why Is Drought Important? Drought is an important forest disturbance that occurs regularly in the Western United States and irregularly in the Eastern United States (Dale and others 2001). Moderate drought stress tends to slow plant growth while severedrought stress can also reduce photosynthesis (Kareiva and others 1993). Drought can also interact with...

  17. A decade of boreal rich fen greenhouse gas fluxes in response to natural and experimental water table variability

    Science.gov (United States)

    Olefeldt, David; Euskirchen, Eugénie S.; Harden, Jennifer W.; Kane, Evan S.; McGuire, A. David; Waldrop, Mark P.; Turetsky, Merritt R.

    2017-01-01

    Rich fens are common boreal ecosystems with distinct hydrology, biogeochemistry and ecology that influence their carbon (C) balance. We present growing season soil chamber methane emission (FCH4), ecosystem respiration (ER), net ecosystem exchange (NEE) and gross primary production (GPP) fluxes from a 9-years water table manipulation experiment in an Alaskan rich fen. The study included major flood and drought years, where wetting and drying treatments further modified the severity of droughts. Results support previous findings from peatlands that drought causes reduced magnitude of growing season FCH4, GPP and NEE, thus reducing or reversing their C sink function. Experimentally exacerbated droughts further reduced the capacity for the fen to act as a C sink by causing shifts in vegetation and thus reducing magnitude of maximum growing season GPP in subsequent flood years by ~15% compared to control plots. Conversely, water table position had only a weak influence on ER, but dominant contribution to ER switched from autotrophic respiration in wet years to heterotrophic in dry years. Droughts did not cause inter-annual lag effects on ER in this rich fen, as has been observed in several nutrient-poor peatlands. While ER was dependent on soil temperatures at 2 cm depth, FCH4 was linked to soil temperatures at 25 cm. Inter-annual variability of deep soil temperatures was in turn dependent on wetness rather than air temperature, and higher FCH4 in flooded years was thus equally due to increased methane production at depth and decreased methane oxidation near the surface. Short-term fluctuations in wetness caused significant lag effects on FCH4, but droughts caused no inter-annual lag effects on FCH4. Our results show that frequency and severity of droughts and floods can have characteristic effects on the exchange of greenhouse gases, and emphasize the need to project future hydrological regimes in rich fens.

  18. Gas exchange patterns and water loss rates in the Table Mountain cockroach, Aptera fusca (Blattodea: Blaberidae).

    Science.gov (United States)

    Groenewald, Berlizé; Bazelet, Corinna S; Potter, C Paige; Terblanche, John S

    2013-10-15

    The importance of metabolic rate and/or spiracle modulation for saving respiratory water is contentious. One major explanation for gas exchange pattern variation in terrestrial insects is to effect a respiratory water loss (RWL) saving. To test this, we measured the rates of CO2 and H2O release ( and , respectively) in a previously unstudied, mesic cockroach, Aptera fusca, and compared gas exchange and water loss parameters among the major gas exchange patterns (continuous, cyclic, discontinuous gas exchange) at a range of temperatures. Mean , and per unit did not differ among the gas exchange patterns at all temperatures (P>0.09). There was no significant association between temperature and gas exchange pattern type (P=0.63). Percentage of RWL (relative to total water loss) was typically low (9.79±1.84%) and did not differ significantly among gas exchange patterns at 15°C (P=0.26). The method of estimation had a large impact on the percentage of RWL, and of the three techniques investigated (traditional, regression and hyperoxic switch), the traditional method generally performed best. In many respects, A. fusca has typical gas exchange for what might be expected from other insects studied to date (e.g. , , RWL and cuticular water loss). However, we found for A. fusca that expressed as a function of metabolic rate was significantly higher than the expected consensus relationship for insects, suggesting it is under considerable pressure to save water. Despite this, we found no consistent evidence supporting the conclusion that transitions in pattern type yield reductions in RWL in this mesic cockroach.

  19. Water use patterns of co-occurring C3 and C4 shrubs in the Gurbantonggut desert in northwestern China.

    Science.gov (United States)

    Tiemuerbieke, Bahejiayinaer; Min, Xiao-Jun; Zang, Yong-Xin; Xing, Peng; Ma, Jian-Ying; Sun, Wei

    2018-09-01

    In water-limited ecosystems, spatial and temporal partitioning of water sources is an important mechanism that facilitates plant survival and lessens the competition intensity of co-existing plants. Insights into species-specific root functional plasticity and differences in the water sources of co-existing plants under changing water conditions can aid in accurate prediction of the response of desert ecosystems to future climate change. We used stable isotopes of soil water, groundwater and xylem water to determine the seasonal and inter- and intraspecific differences variations in the water sources of six C 3 and C 4 shrubs in the Gurbantonggut desert. We also measured the stem water potentials to determine the water stress levels of each species under varying water conditions. The studied shrubs exhibited similar seasonal water uptake patterns, i.e., all shrubs extracted shallow soil water recharged by snowmelt water during early spring and reverted to deeper water sources during dry summer periods, indicating that all of the studied shrubs have dimorphic root systems that enable them to obtain water sources that differ in space and time. Species in the C 4 shrub community exhibited differences in seasonal water absorption and water status due to differences in topography and rooting depth, demonstrating divergent adaptations to water availability and water stress. Haloxylon ammodendron and T. ramosissima in the C 3 /C 4 mixed community were similar in terms of seasonal water extraction but differed with respect to water potential, which indicated that plant water status is controlled by both root functioning and shoot eco-physiological traits. The two Tamarix species in the C 3 shrub community were similar in terms of water uptake and water status, which suggests functional convergence of the root system and physiological performance under same soil water conditions. In different communities, Haloxylon ammodendron differed in terms of summer water extraction

  20. Isotopic fractionation of soil water during the evaporation process in the presence of a phreatic water table

    International Nuclear Information System (INIS)

    Leopoldo, P.R.; Stolf, R.

    1979-01-01

    This experiment was conducted with columns of soil, constitued by alluvion sediment keeping a phreatic watertable at a depth of 40 cm and constant water supply, and its objective was to check the water behaviour as to its deuterium and oxigen content when moving from the lower layers to the upper layers, and consequent loss to the atmosphere through evaporation. It was noted that the existing D and 18 O content in the water forming the phreativ watertable practivally does not vary with this process. In addition to the observations on soil columns, soil water from the Brasilian northeastern region was collected and analysed. The phreatic watertable at the collecting site lay at a depth of about 40-50 cm. Preliminarily, it was noted that these results apparently indicate an excess evaporation, and are also consistent with those obtained by other investigators, who proposed the use of stable isotopes to study problems related to salinization of water in this region. (Author) [pt

  1. Water, Water Everywhere but is it Safe to Drink? Some Detrimental Health Effects Associated with Consumption of Groundwater Enriched in Naturally-Occurring Contaminants

    Science.gov (United States)

    Fuge, R.

    2007-05-01

    Drinking water represents a major pathway of trace elements into the human body. As such, groundwaters, the chemistry of which reflect water/rock interaction, can be a source of trace elements which will have a marked health effect on humans consuming them. Health problems associated with the consumption of groundwater enriched in various elements and compounds have been recorded for many years. For example, high-arsenic groundwaters used for public water supply were first associated with harmful health effects as early as 1917 in Córdoba Province in Argentina, where the local population suffered from skin disorders. Subsequently, in the 1960s consumption of high-arsenic groundwaters was identified as a factor in the aetiology of "black foot disease", an endemic vascular disease, in Taiwan. However, it is problems associated with the very high-arsenic groundwaters of the highly populous Ganges delta area of Bangladesh and West Bengal that has more recently highlighted the health problem of consuming high-arsenic waters. The most obvious problems of excess arsenic consumption through drinking water are arsenical skin lesions, the severity of which being generally correlated with arsenic content of the water. A high incidence of cancers of the skin, bladder and other organs has been recorded in the high-arsenic drinking water areas of the world. A high incidence of vascular disease, found in the arsenic-rich area of Taiwan, has also been shown to occur in Bangladesh. In addition, it has been suggested that high arsenic in drinking water results in increased incidence of diabetes mellitus. Fluorine is another element long recognised as having a major effect on the well-being of humans. Consumption of high-fluorine waters were first identified as having a detrimental effect on teeth in the 1920s and 30s. It was subsequently shown that where fluorine is present in drinking waters at concentrations of around 0.5 to 1 mg/L it can have beneficial effects on humans

  2. Methane transport and emissions from soil as affected by water table and vascular plants

    OpenAIRE

    Bhullar, Gurbir S; Iravani, Majid; Edwards, Peter J; Olde Venterink, Harry

    2013-01-01

    Background: The important greenhouse gas (GHG) methane is produced naturally in anaerobic wetland soils. By affecting the production, oxidation and transport of methane to the atmosphere, plants have a major influence upon the quantities emitted by wetlands. Different species and functional plant groups have been shown to affect these processes differently, but our knowledge about how these effects are influenced by abiotic factors such as water regime and temperature remains limited. Here...

  3. SIMULATION OF THE BEHAVIOR OF THE WATER TABLE IN A COASTAL AQUIFER SYSTEM FINITE ELEMENT

    Directory of Open Access Journals (Sweden)

    Luis Lara Romero

    2016-06-01

    Full Text Available This paper presents the application of Galerkin method to discretize the model equation of groundwater ow in a conned aquifer semipermeable with tidal boundary conditions on one of its borders, the other borders remain constant. For the simulations was generated a numerical program, Ground Water Finite Element Method, which implements the method of nite elements with triangular elements with three nodes and a degree of freedom per node.

  4. Environmental Monitoring, Water Quality - MO 2009 Water Quality Standards - Table G Lake Classifications and Use Designations (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — This data set contains Missouri Water Quality Standards (WQS) lake classifications and use designations described in the Missouri Code of State Regulations (CSR), 10...

  5. Water uptake and transport in lianas and co-occurring trees of a seasonally dry tropical forest.

    Science.gov (United States)

    José Luis Andrade; Frederick C. Meinzer; Guillermo Goldstein; Stefan A. Schnitzer

    2005-01-01

    Water uptake and transport were studied in eight liana species in a seasonally dry tropical forest on Barro Colorado Island, Panama. Stable hydrogen isotope composition (δD) of xylem and soil water, soil volumetric water content (θv), and basal sap flow were measured during the 1997 and...

  6. Effect of the spatial distribution of physical aquifer properties on modelled water table depth and stream discharge in a headwater catchment

    Directory of Open Access Journals (Sweden)

    C. Gascuel-Odoux

    2010-07-01

    Full Text Available Water table depth and its dynamics on hillslopes are often poorly predicted despite they control both water transit time within the catchment and solute fluxes at the catchment outlet. This paper analyses how relaxing the assumption of lateral homogeneity of physical properties can improve simulations of water table depth and dynamics. Four different spatial models relating hydraulic conductivity to topography have been tested: a simple linear relationship, a linear relationship with two different topographic indexes, two Ks domains with a transitional area. The Hill-Vi model has been modified to test these hypotheses. The studied catchment (Kervidy-Naizin, Western France is underlain by schist crystalline bedrock. A shallow and perennial groundwater highly reactive to rainfall events mainly develops in the weathered saprolite layer. The results indicate that (1 discharge and the water table in the riparian zone are similarly predicted by the four models, (2 distinguishing two Ks domains constitutes the best model and slightly improves prediction of the water table upslope, and (3 including spatial variations in the other parameters such as porosity or rate of hydraulic conductivity decrease with depth does not improve the results. These results underline the necessity of better investigations of upslope areas in hillslope hydrology.

  7. Water Table Management Reduces Tile Nitrate Loss in Continuous Corn and in a Soybean-Corn Rotation

    Directory of Open Access Journals (Sweden)

    Craig F. Drury

    2001-01-01

    Full Text Available Water table management systems can be designed to alleviate soil water excesses and deficits, as well as reduce nitrate leaching losses in tile discharge. With this in mind, a standard tile drainage (DR system was compared over 8 years (1991 to 1999 to a controlled tile drainage/subirrigation (CDS system on a low-slope (0.05 to 0.1% Brookston clay loam soil (Typic Argiaquoll in southwestern Ontario, Canada. In the CDS system, tile discharge was controlled to prevent excessive drainage, and water was pumped back up the tile lines (subirrigation to replenish the crop root zone during water deficit periods. In the first phase of the study (1991 to 1994, continuous corn (Zea mays, L. was grown with annual nitrogen (N fertilizer inputs as per local soil test recommendations. In the second phase (1995 to 1999, a soybean (Glycine max L., Merr.-corn rotation was used with N fertilizer added only during the two corn years. In Phase 1 when continuous corn was grown, CDS reduced total tile discharge by 26% and total nitrate loss in tile discharge by 55%, compared to DR. In addition, the 4-year flow weighted mean (FWM nitrate concentration in tile discharge exceeded the Canadian drinking water guideline (10 mg N l–1 under DR (11.4 mg N l–1, but not under CDS (7.0 mg N l–1. In Phase 2 during the soybean-corn rotation, CDS reduced total tile discharge by 38% and total nitrate loss in tile discharge by 66%, relative to DR. The 4-year FWM nitrate concentration during Phase 2 in tile discharge was below the drinking water guideline for both DR (7.3 mg N l–1 and CDS (4.0 mg N l–1. During both phases of the experiment, the CDS treatment caused only minor increases in nitrate loss in surface runoff relative to DR. Hence CDS decreased FWM nitrate concentrations, total drainage water loss, and total nitrate loss in tile discharge relative to DR. In addition, soybean-corn rotation reduced FWM nitrate concentrations and total nitrate loss in tile discharge

  8. Fractal water quality fluctuations spanning the periodic table in an intensively farmed watershed.

    Science.gov (United States)

    Aubert, Alice H; Kirchner, James W; Gascuel-Odoux, Chantal; Faucheux, Mikael; Gruau, Gérard; Mérot, Philippe

    2014-01-21

    Recently developed measurement technologies can monitor surface water quality almost continuously, creating high-frequency multiparameter time series and raising the question of how best to extract insights from such rich data sets. Here we use spectral analysis to characterize the variability of water quality at the AgrHys observatory (Western France) over time scales ranging from 20 min to 12 years. Three years of daily sampling at the intensively farmed Kervidy-Naizin watershed reveal universal 1/f scaling for all 36 solutes, yielding spectral slopes of 1.05 ± 0.11 (mean ± standard deviation). These 36 solute concentrations show varying degrees of annual cycling, suggesting different controls on watershed export processes. Twelve years of daily samples of SO4, NO3, and dissolved organic carbon (DOC) show that 1/f scaling does not continue at frequencies below 1/year in those constituents, whereas a 12-year daily record of Cl shows a general 1/f trend down to the lowest measurable frequencies. Conversely, approximately 12 months of 20 min NO3 and DOC measurements show that at frequencies higher than 1/day, the spectra of these solutes steepen to slopes of roughly 3, and at time scales shorter than 2-3 h, the spectra flatten to slopes near zero, reflecting analytical noise. These results confirm and extend the recent discovery of universal fractal 1/f scaling in water quality at the relatively pristine Plynlimon watershed in Wales, further demonstrating the importance of advective-dispersive transport mixing in catchments. However, the steeper scaling at subdaily time scales suggests additional short-term damping of solute concentrations, potentially due to in-stream or riparian processes.

  9. BOREAS TGB-1/TGB-3 Water Table and Peat Temperature Data over the NSA

    Science.gov (United States)

    Bubier, Jill L.; Comer, Neil; Moore, Tim R.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

    2000-01-01

    The BOREAS TGB-1 and TGB-3 teams collected several data sets that contributed to understanding the measured trace gas fluxes over sites in the NSA. This data set contains continuous and manual measurements of water level and air and soil temperatures at the four subsites within the NSA Tower Fen site complex. The measurements were taken to understand the thermal and hydrological gradients associated with each plant community present in the fen. Measurements were taken from May to September 1994 and May to October 1996. The data are provided in tabular ASCII files.

  10. Performance of methods for estimation of table beet water requirement in Alagoas

    Directory of Open Access Journals (Sweden)

    Daniella P. dos Santos

    Full Text Available ABSTRACT Optimization of water use in agriculture is fundamental, particularly in regions where water scarcity is intense, requiring the adoption of technologies that promote increased irrigation efficiency. The objective of this study was to evaluate evapotranspiration models and to estimate the crop coefficients of beet grown in a drainage lysimeter in the Agreste region of Alagoas. The experiment was conducted at the Campus of the Federal University of Alagoas - UFAL, in the municipality of Arapiraca, AL, between March and April 2014. Crop evapotranspiration (ETc was estimated in drainage lysimeters and reference evapotranspiration (ETo by Penman-Monteith-FAO 56 and Hargreaves-Samani methods. The Hargreaves-Samani method presented a good performance index for ETo estimation compared with the Penman-Monteith-FAO method, indicating that it is adequate for the study area. Beet ETc showed a cumulative demand of 202.11 mm for a cumulative reference evapotranspiration of 152.00 mm. Kc values determined using the Penman-Monteith-FAO 56 and Hargreaves-Samani methods were overestimated, in comparison to the Kc values of the FAO-56 standard method. With the obtained results, it is possible to correct the equations of the methods for the region, allowing for adequate irrigation management.

  11. Long-term Water Table Monitoring of Rio Grande Riparian Ecosystems for Restoration Potential Amid Hydroclimatic Challenges

    Science.gov (United States)

    Thibault, James R.; Cleverly, James R.; Dahm, Clifford N.

    2017-12-01

    Hydrological processes drive the ecological functioning and sustainability of cottonwood-dominated riparian ecosystems in the arid southwestern USA. Snowmelt runoff elevates groundwater levels and inundates floodplains, which promotes cottonwood germination. Once established, these phreatophytes rely on accessible water tables (WTs). In New Mexico's Middle Rio Grande corridor diminished flooding and deepening WTs threaten native riparian communities. We monitored surface flows and riparian WTs for up to 14 years, which revealed that WTs and surface flows, including peak snowmelt discharge, respond to basin climate conditions and resource management. WT hydrographs influence the composition of riparian communities and can be used to assess if potential restoration sites meet native vegetation tolerances for WT depths, rates of recession, and variability throughout their life stages. WTs were highly variable in some sites, which can preclude native vegetation less adapted to deep drawdowns during extended droughts. Rates of WT recession varied between sites and should be assessed in regard to recruitment potential. Locations with relatively shallow WTs and limited variability are likely to be more viable for successful restoration. Suitable sites have diminished greatly as the once meandering Rio Grande has been constrained and depleted. Increasing demands on water and the presence of invasive vegetation better adapted to the altered hydrologic regime further impact native riparian communities. Long-term monitoring over a range of sites and hydroclimatic extremes reveals attributes that can be evaluated for restoration potential.

  12. Soil chemistry and ground-water quality of the water-table zone of the surficial aquifer, Naval Submarine Base Kings Bay, Camden County, Georgia, 1998 and 1999

    Science.gov (United States)

    Leeth, David C.

    2002-01-01

    In 1998, the U.S. Geological Survey, in cooperation with the U.S. Department of the Navy, began an investigation to determine background ground-water quality of the water-table zone of the surficial aquifer and soil chemistry at Naval Submarine Base Kings Bay, Camden County, Georgia, and to compare these data to two abandoned solid- waste disposal areas (referred to by the U.S. Navy as Sites 5 and 16). The quality of water in the water-table zone generally is within the U.S. Environmental Protection Agency (USEPA) drinking-water regulation. The pH of ground water in the study area ranged from 4.0 to 7.6 standard units, with a median value of 5.4. Water from 29 wells is above the pH range and 3 wells are within the range of the USEPA secondary drinking-water regulation (formerly known as the Secondary Maximum Contaminant Level or SMCL) of 6.5 to 8.5 standard units. Also, water from one well at Site 5 had a chloride concentration of 570 milligrams per liter (mg/L,), which is above the USEPA secondary drinking-water regulation of 250 mg/L. Sulfate concentrations in water from two wells at Site 5 are above the USEPA secondary drinking-water regulation of 250 mg/L. Of 22 soil-sampling locations for this study, 4 locations had concentrations above the detection limit for either volatile organic compounds (VOCs), base-neutral acids (BNAs), or pesticides. VOCs detected in the study area include toluene in one background sample; and acetone in one background sample and one sample from Site 16--however, detection of these two compounds may be a laboratory artifact. Pesticides detected in soil at the Submarine Base include two degradates of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT): 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (4,4'-DDD) in one background sample, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethene (4,4'-DDE) in one background sample and one sample from Site 16; and dibenzofuran in one sample from Site 16. BNAs were detected in one background sample and in two

  13. Polder effects on sediment-to-soil conversion: water table, residual available water capacity, and salt stress interdependence.

    Science.gov (United States)

    Radimy, Raymond Tojo; Dudoignon, Patrick; Hillaireau, Jean Michel; Deboute, Elise

    2013-01-01

    The French Atlantic marshlands, reclaimed since the Middle Age, have been successively used for extensive grazing and more recently for cereal cultivation from 1970. The soils have acquired specific properties which have been induced by the successive reclaiming and drainage works and by the response of the clay dominant primary sediments, that is, structure, moisture, and salinity profiles. Based on the whole survey of the Marais Poitevin and Marais de Rochefort and in order to explain the mechanisms of marsh soil behavior, the work focuses on two typical spots: an undrained grassland since at least 1964 and a drained cereal cultivated field. The structure-hydromechanical profiles relationships have been established thanks to the clay matrix shrinkage curve. They are confronted to the hydraulic functioning including the fresh-to-salt water transfers and to the recording of tensiometer profiles. The CE1/5 profiles supply the water geochemical and geophysical data by their better accuracy. Associated to the available water capacity calculation they allow the representation of the parallel evolution of the residual available water capacity profiles and salinity profiles according to the plant growing and rooting from the mesophile systems of grassland to the hygrophile systems of drained fields.

  14. Polder Effects on Sediment-to-Soil Conversion: Water Table, Residual Available Water Capacity, and Salt Stress Interdependence

    Directory of Open Access Journals (Sweden)

    Raymond Tojo Radimy

    2013-01-01

    Full Text Available The French Atlantic marshlands, reclaimed since the Middle Age, have been successively used for extensive grazing and more recently for cereal cultivation from 1970. The soils have acquired specific properties which have been induced by the successive reclaiming and drainage works and by the response of the clay dominant primary sediments, that is, structure, moisture, and salinity profiles. Based on the whole survey of the Marais Poitevin and Marais de Rochefort and in order to explain the mechanisms of marsh soil behavior, the work focuses on two typical spots: an undrained grassland since at least 1964 and a drained cereal cultivated field. The structure-hydromechanical profiles relationships have been established thanks to the clay matrix shrinkage curve. They are confronted to the hydraulic functioning including the fresh-to-salt water transfers and to the recording of tensiometer profiles. The CE1/5 profiles supply the water geochemical and geophysical data by their better accuracy. Associated to the available water capacity calculation they allow the representation of the parallel evolution of the residual available water capacity profiles and salinity profiles according to the plant growing and rooting from the mesophile systems of grassland to the hygrophile systems of drained fields.

  15. Changes in soluble metal concentrations induced by variable water table levels as response to liming and Phragmites australis growth in metal-polluted wetland soils: Management effectiveness

    NARCIS (Netherlands)

    Gonzalez Alcaraz, M.N.; van Gestel, C.A.M.

    2016-01-01

    This study aimed to assess the effectiveness of liming and Phragmites australis growth for the management of metal-polluted wetland soils under fluctuating water table levels. Soil columns (20 cm in diameter and 60 cm high) were constructed with two soil types (pH ~ 6.4 and pH ~ 3.1) and four

  16. Mobility and transport of mercury and methylmercury in peat as a function of changes in water table regime and plant functional groups

    Science.gov (United States)

    Kristine M. Haynes; Evan S. Kane; Lynette Potvin; Erik A. Lilleskov; Randy Kolka; Carl P. J. Mitchell

    2017-01-01

    Climate change is likely to significantly affect the hydrology, ecology, and ecosystem function of peatlands, with potentially important but unclear impacts on mercury mobility within and transport from peatlands. Using a full-factorial mesocosm approach, we investigated the potential impacts on mercury mobility of water table regime changes (high and low) and...

  17. Design and analysis of a SVE system in a shallow water table application

    International Nuclear Information System (INIS)

    Swingle, T.P.; Leachman, W.D.

    1995-01-01

    Cummins Southeastern Power, Inc. (CSPI) operates a diesel engine repair facility in Hialeah Gardens, FL. Parsons Engineering Science, Inc. (Parsons ES) was retained to design a treatment system to remediate soil and hydrocarbons beneath the CSPI service building. Soil vapor extraction (SVE) followed by bioventing was selected as the most appropriate and cost effective approach. These activities were completed as part of CSPI's overall environmental program, which includes cleanup of any contamination that is encountered at their facilities and continual implementation of new measures to prevent future contamination from occurring. This paper presents a complete case history outlining the unique technical challenges associated with the CSPI site conditions. The methods utilized during completion and analysis of the pilot test are discussed and a description of how the pilot data was utilized for completion of the full-scale design is included. The paper presents the empirical analysis method which was developed during this design and shows how it can be applied to other SVE remediation applications

  18. Use of naturally occurring helium to estimate ground-water velocities for studies of geologic storage of radioactive waste

    International Nuclear Information System (INIS)

    Marine, I.W.

    1977-01-01

    In a study of the potential for storing radioactive waste in metamorphic rock at the Savannah River Plant near Aiken, South Carolina, the rate of water movement was determined to be about 0.06 m/y by analyzing gas dissolved in the water. The gas contained up to 6 percent helium, which originated from the radioactive decay of natural uranium and thorium in the crystalline rock. The residence time of the water in the rock was calculated to be 840,000 years from the quantity of uranium and thorium in the rock, their rates of radioactive decay, and the quantity of helium dissolved in the water. The estimation of ground-water velocities by the helium method is more applicable to the assessment of a geologic site for storage of radioactive waste than are velocities estimated from packer tests, pumping tests, or artificial tracer tests, all of which require extensive time and space extrapolations

  19. Water table and species identity outweigh carbon and nitrogen availability in a softwater plant community

    Science.gov (United States)

    Vanderhaeghe, Floris; Smolders, Alfons J. P.; Roelofs, Jan G. M.; Hoffmann, Maurice

    2013-02-01

    Performance of aquatic macrophytes is driven by many environmental factors, and a major challenge is to understand how aquatic macrophyte communities are structured in various environments. In softwater lakes in Western Europe, hydrological state (submersed/emersed), carbon dioxide and ammonium levels and species interactions are considered as driving forces in structuring amphibious plant communities. In this study we aimed at evaluating the relative importance of these factors for four species in a competitive neighbourhood. Softwater lake habitat was simulated during one growing season in laboratory conditions, mimicking water level fluctuation, photoperiod and temperature. Artificial communities consisted of small populations of four softwater macrophyte species: Luronium natans, Baldellia ranunculoides ssp. repens, Eleocharis multicaulis and Hydrocotyle vulgaris. These communities were subjected to two levels of carbon dioxide and ammonium. Additionally, monocultures of Baldellia and Eleocharis were grown at a higher nutrient level combination in order to measure their competitive response in a community. Time (hydrological state) and species identity turned out to be the only consistently significant factors determining community composition. Plant performance was clearly species-dependent, while carbon dioxide and ammonium did not have major effects. The competitive response was significant in both Eleocharis and Baldellia. Competition intensity was highest in the emersed state. Carbon dioxide had a supplementary effect on the within-species performance in Luronium, Baldellia and Eleocharis, with high carbon dioxide level mainly resulting in more flowers and more stolons. Community outcomes and competitive responses in aquatic macrophytes appear difficult to predict, because of mixed life strategies and morphological and functional plasticity. We conclude that hydrological state was the only important environmental factor. The identity of the species that

  20. Hydrogeologic characteristics and geospatial analysis of water-table changes in the alluvium of the lower Arkansas River Valley, southeastern Colorado, 2002, 2008, and 2015

    Science.gov (United States)

    Holmberg, Michael J.

    2017-05-15

    The U.S. Geological Survey in cooperation with the Lower Arkansas Valley Water Conservancy District measures groundwater levels periodically in about 100 wells completed in the alluvial material of the Arkansas River Valley in Pueblo, Crowley, Otero, Bent, and Prowers Counties in southeastern Colorado, of which 95 are used for the analysis in this report. The purpose of this report is to provide information to water-resource administrators, managers, planners, and users about groundwater characteristics in the alluvium of the lower Arkansas Valley extending roughly 150 miles between Pueblo Reservoir and the Colorado-Kansas State line. This report includes three map sheets showing (1) bedrock altitude at the base of the alluvium of the lower Arkansas Valley; (2) estimated spring-to-spring and fall-to-fall changes in water-table altitude between 2002, 2008, and 2015; and (3) estimated saturated thickness in the alluvium during spring and fall of 2002, 2008, and 2015, and thickness of the alluvium in the lower Arkansas Valley. Water-level changes were analyzed by geospatial interpolation methods.Available data included all water-level measurements made between January 1, 2001, and December 31, 2015; however, only data from fall and spring of 2002, 2008, and 2015 are mapped in this report. To account for the effect of John Martin Reservoir in Bent County, Colorado, lake levels at the reservoir were assigned to points along the approximate shoreline and were included in the water-level dataset. After combining the water-level measurements and lake levels, inverse distance weighting was used to interpolate between points and calculate the altitude of the water table for fall and spring of each year for comparisons. Saturated thickness was calculated by subtracting the bedrock surface from the water-table surface. Thickness of the alluvium was calculated by subtracting the bedrock surface from land surface using a digital elevation model.In order to analyze the response

  1. Evaluation of a mechanistic algorithm to calculate the influence of a shallow water table on hydrology sediment and pesticide transport through vegetative filter strips

    Science.gov (United States)

    Lauvernet, C.; Munoz-Carpena, R.; Carluer, N.

    2012-04-01

    Natural or introduced areas of vegetation, also known as vegetative filter strips (VFS), are a common environmental control practice to protect surface water bodies from human influence. In Europe, VFS are placed along the water network to protect from agrochemical drift during applications, in addition to runoff control. Their bottomland placement next to the streams often implies the presence of a seasonal shallow water table which can have a profound impact on the efficiency of the buffer zone (Lacas et al. 2005). A physically-based algorithm describing ponded infiltration into soils bounded by a water table, proposed by Salvucci and Enthekabi (1995), was further developed to simulate VFS dynamics by making it explicit in time, account for unsteady rainfall conditions, and by coupling to a numerical overland flow and transport model (VFSMOD) (Munoz-Carpena et al., submitted). In this study, we evaluate the importance of the presence of a shallow water table on filter efficiency (reductions in runoff, sediment and pesticide mass), in the context of all other input factors used to describe the system. Global sensitivity analysis (GSA) was used to rank the important input factors and the presence of interactions, as well as the contribution of the important factors to the output variance. GSA of VSFMOD modified for shallow water table was implemented on 2 sites selected in France because they represent different agro-pedo-climatic conditions for which we can compare the role of the factors influencing the performance of grassed buffer strips for surface runoff, sediment and pesticide removal. The first site at Morcille watershed in the Beaujolais wineyard (Rhône-Alpes) contains a very permeable sandy-clay with water table depth varying with the season (very deep in summer and shallow in winter), with a high slope (20 to 30%), and subject to strong seasonal storms (semi-continental, Mediterranean climate). The second site at La Jailliere (Loire-Atlantique, ARVALIS

  2. Water table depth fluctuations during ENSO phenomenon on different tropical peat swamp forest land covers in Katingan, Indonesia

    Science.gov (United States)

    Rossita, A.; Witono, A.; Darusman, T.; Lestari, D. P.; Risdiyanto, I.

    2018-03-01

    As it is the main role to maintain hydrological function, peatland has been a limelight since drainage construction for agriculture evolved. Drainage construction will decrease water table depth (WTD) and result in CO2 emission release to the atmosphere. Regardless of human intervention, WTD fluctuations can be affected by seasonal climate and climate variability, foremost El Niño Southern Oscillation (ENSO). This study aims to determine the correlation between rainfall in Katingan and ENSO index, analyze the pattern of WTD fluctuation of open area and forest area in 2015 (during very strong El Niño) and 2016 (during weak La Niña), calculate the WTD trendline slope during the dry season, and rainfall and WTD correlation. The result showed that open area has a sharper slope of decreasing or increasing WTD when entering the dry, compared to the forest area. Also, it is found that very strong El Niño in 2015 generated a pattern of more extreme decreasing WTD during the dry season than weak La Niña in 2016.

  3. The reconstruction of late Holocene depth-to-water-table based on testate amoebae in an eastern Australian mire

    Science.gov (United States)

    Zheng, X.; Money, S.; Hope, G.

    2017-12-01

    There are relatively few quantitative palaeo-hydrological records available in eastern Australia, and those that are available, for example from dendroclimatology and the reconstruction of lake level, are often relatively short or have a relatively coarse temporal resolution (e.g. Wilkins et al. 2013; Palmer et al. 2015). Testate amoebae, a widely used hydrological proxy in the Northern Hemisphere, were used here to reconstruct depth to water table (DWT) at Snowy Flat, which is a Sphagnum-Richea-Empodismahigh altitude (1618 m asl) shrub bog in the Australian Capital Territory, Australia. Testate amoebae were quantified in a Snowy Flat core representing 4,200 cal Y BP and the community composition was used to reconstruct DWT based on our recently established transfer functions. Results from three different types of transfer functions (Fig. 1) consistently show there was a decreasing DWT (wetter) period centred on about 3350 cal Y BP, a trend towards increased dryness from about 3300 to 2200 cal Y BP and a distinctly drier period 850 to 700 cal Y BP which was immediately followed by a wetter period from 700 to 500 cal Y BP. We discuss these episodes and trends in relation to the drivers of climatic variability in this region and in particular, by comparing our results with other south-eastern Australia records, comment on the history of the southern annular mode.

  4. Why chlorate occurs in potable water and processed foods: a critical assessment and challenges faced by the food industry.

    Science.gov (United States)

    Kettlitz, Beate; Kemendi, Gabriella; Thorgrimsson, Nigel; Cattoor, Nele; Verzegnassi, Ludovica; Le Bail-Collet, Yves; Maphosa, Farai; Perrichet, Aurélie; Christall, Birgit; Stadler, Richard H

    2016-06-01

    Recently, reports have been published on the occurrence of chlorate mainly in fruits and vegetables. Chlorate is a by-product of chlorinating agents used to disinfect water, and can be expected to be found in varying concentrations in drinking water. Data on potable water taken at 39 sampling points across Europe showed chlorate to range from foods of 0.01 mg kg(-1). This default MRL has now led to significant problems in the EU, where routinely disinfected water, used in the preparation of food products such as vegetables or fruits, leaves chlorate residues in excess of the default MRL, and in strict legal terms renders the food unmarketable. Due to the paucity of data on the chlorate content of prepared foods in general, we collated chlorate data on more than 3400 samples of mainly prepared foods, including dairy products, meats, fruits, vegetables and different food ingredients/additives. In total, 50.5% of the food samples contained chlorate above 0.01 mg kg(-1), albeit not due to the use of chlorate as a pesticide but mainly due to the occurrence of chlorate as an unavoidable disinfectant by-product. A further entry point of chlorate into foods may be via additives/ingredients that may contain chlorate as a by-product of the manufacturing process (e.g. electrolysis). Of the positive samples in this study, 22.4% revealed chlorate above 0.1 mg kg(-1). In the absence of EU levels for chlorate in water, any future EU regulations must consider the already available WHO guideline value of 0.7 mg l(-1) in potable water, and the continued importance of the usage of oxyhalides for disinfection purposes.

  5. Use of geospatial technology for delineating groundwater potential zones with an emphasis on water-table analysis in Dwarka River basin, Birbhum, India

    Science.gov (United States)

    Thapa, Raju; Gupta, Srimanta; Gupta, Arindam; Reddy, D. V.; Kaur, Harjeet

    2018-05-01

    Dwarka River basin in Birbhum, West Bengal (India), is an agriculture-dominated area where groundwater plays a crucial role. The basin experiences seasonal water stress conditions with a scarcity of surface water. In the presented study, delineation of groundwater potential zones (GWPZs) is carried out using a geospatial multi-influencing factor technique. Geology, geomorphology, soil type, land use/land cover, rainfall, lineament and fault density, drainage density, slope, and elevation of the study area were considered for the delineation of GWPZs in the study area. About 9.3, 71.9 and 18.8% of the study area falls within good, moderate and poor groundwater potential zones, respectively. The potential groundwater yield data corroborate the outcome of the model, with maximum yield in the older floodplain and minimum yield in the hard-rock terrains in the western and south-western regions. Validation of the GWPZs using the yield of 148 wells shows very high accuracy of the model prediction, i.e., 89.1% on superimposition and 85.1 and 81.3% on success and prediction rates, respectively. Measurement of the seasonal water-table fluctuation with a multiplicative model of time series for predicting the short-term trend of the water table, followed by chi-square analysis between the predicted and observed water-table depth, indicates a trend of falling groundwater levels, with a 5% level of significance and a p-value of 0.233. The rainfall pattern for the last 3 years of the study shows a moderately positive correlation ( R 2 = 0.308) with the average water-table depth in the study area.

  6. The Effect of Water Table Fluctuation and its Salinity on Fe Crystal and Noncrystal in some Khuzestan Soils

    Directory of Open Access Journals (Sweden)

    mostafa Pajohannia

    2017-01-01

    Full Text Available Introduction: Iron is found in different forms in the soil. In the primary minerals, iron is found as Fe3+ or Fe2+ which converted to Fe2+ and released in unsuitable reduction conditions. Minerals such as sulfide or chlorine and bicarbonate can affect and change the different forms soil Fe. FeAs these elements are abundance in groundwater or soil, they are capable to react chemically with Fe and change different Fe forms and also may deposit or even leach them by increasing its solubility in the soil. Water table fluctuation is a regular phenomenon in Khuzestan that Fe forms change under these situations. The study of Fe oxide forms and its changes can be applied for evaluation of soil development. Therefore, the aim of this study is the water table fluctuation and its quality effects, and some physio-chemical properties on Fe oxides forms in non-saline and saline soils in Khuzestan. Materials and Methods: Soil samples were collected from two regions: saline (Abdolkhan and non-saline (South Susa regions. soil samples were collected from all horizons of 12 soil field studied profiles . The samples were analyzed for soil texture, pH, EC (soil: water ratio 1:5, organic carbon and aggregate stability (Kemper and Rosenau method. Fe forms also were extracted by two methods in all samples: di-tyonite sodium and ammonium oxalate extraction. Fe oxalate extracted was related to Feo (non crystal Fe and Fed-Feo was related to Fec (crystalline Fe. The Fe content were determined by atomic absorbtion spectrophotometer (AAS. Data were analysis in SAS and Excel software and results were presented. Results and Discussion: The results showed that texture were loamy sand to silty clay loam, OM was very poor (0.1-0.7%. The soil salinity was also 2.8-16.8 dS/m. Calcium carbonate equivalent was 38-40%. All pedons were classified in Entisols and Inceptisols according to Keys to soil taxonomy (2010. The results showed that the proportion of Fe with oxalate to di

  7. Does localized recharge occur at a discharge area within the ground-water flow system of Yucca Mountain, Nevada?

    International Nuclear Information System (INIS)

    Czarnecki, J.B.; Kroitoru, L.; Ronen, D.; Magaritz, M.

    1992-01-01

    Studies done in 1984, at a central site on Franklin Lake playa (also known as Alkali Flat, a major discharge area of the ground-water flow system that includes Yucca Mountain, Nevada, the potential site of a high-level nuclear-waste repository) yield limited hydraulic-head and hydrochemical data from a 3-piezometer nest which indicated a slightly downward hydraulic gradient (-0.02) and decreasing concentration of dissolved solids with increasing depth. Hydraulic-head measurements in June, 1989 made at the piezometer nest showed a substantially larger downward gradient (-0.10) and a 0. 83-meter higher water level in the shallowest piezometer (3.29 meters deep), indicating the possibility of localized recharge. during the period of September-November, 1989, a multilevel sampler was used to obtain detailed hydrochemical profiles of the uppermost 1. 5 m of the saturated zone

  8. Synthesis of the IRSN report on the issue of severe accidents which may occur on operating pressurised water nuclear reactors

    International Nuclear Information System (INIS)

    2008-01-01

    While containing other related documents (expert report, mail), this synthetic report analyses and comments some aspects of the assessment and treatment of severe accidents by EDF in its operating PWRs (pressurised water nuclear reactors). These aspects are: the EDF referential related to severe accidents (objectives of consequence limitation and prevention, long term management, probabilistic objectives, radiological objectives, expected performance of equipment and systems), the re-assessment of the 'S3 reference source term' which corresponds to a typical discharge (selection of representative scenarios, new approach based on waste categorization, the taking into account of various species, components and systems), the water management in the reactor tank (risks of explosion, of critical corium level, etc.), the strategy of an anticipated opening of the containment envelope venting-filtration device in order to avoid a core fusion, and the risk associated by a cesspool filling-in by debris

  9. Comparison of groundwater transit velocity estimates from flux theory and water table recession based approaches for solute transport.

    Science.gov (United States)

    Rasiah, Velu; Armour, John David

    2013-02-15

    Reliable information in transit time (TT) derived from transit velocity (TV) for rain or irrigation water to mix with groundwater (GW) and the subsequent discharge to surface water bodies (SWB) is essential to address the issues associated with the transport of nutrients, particularly nitrate, from GW to SWB. The objectives of this study are to (i) compare the TV estimates obtained using flux theory-based (FT) approach with the water table rise/recession (WT) rate approach and (ii) explore the impact of the differences on solute transport from GW to SWB. The results from a study conducted during two rainy seasons in the northeast humid tropics of Queensland, Australia, showed the TV varied in space and over time and the variations depended on the estimation procedures. The lateral TV computed using the WT approach ranged from 1.00 × 10(-3) to 2.82 × 10(-1) m/d with a mean of 6.18 × 10(-2) m/d compared with 2.90 × 10(-4) to 5.15 × 10(-2) m/d for FT with a mean of 2.63 × 10(-2) m/d. The vertical TV ranged from 2.00 × 10(-3) to 6.02 × 10(-1) m/d with a mean of 1.28 × 10(-1) m/d for the WT compared with 6.76 × 10(-3)-1.78 m/d for the FT with a mean of 2.73 × 10(-1) m/d. These differences are attributed to the role played by different flow pathways. The bypass flow pathway played a role only in WT but not in FT. Approximately 86-95% of the variability in lateral solute transport was accounted for by the lateral TV and the total recession between two consecutive major rainfall events. A comparison of TT from FT and WT approaches indicated the laterally transported nitrate from the GW to the nearby creek was relatively 'new', implying the opportunity for accumulation and to undergo biochemical reactions in GW was low. The results indicated the WT approach produced more reliable TT estimates than FT in the presence of bypass flow pathways. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Early occurring and continuing effects

    International Nuclear Information System (INIS)

    Scott, B.R.; Hahn, F.F.

    1985-01-01

    This chapter deals with health-risk estimates for early and continuing effects of exposure to ionizing radiations that could be associated with light water nuclear power plants accidents. Early and continuing effects considered are nonneoplastic diseases and symptoms that normally occur soon after radiation exposure, but may also occur after years have passed. They are generally associated with relatively high (greater than 1 Gy) doses. For most of the effects considered, there is a practical dose threshold. Organs of primary interest, because of their high sensitivity or the likelihood of receiving a large radiation dose, are bone marrow, gastrointestinal tract, thyroid glands, lungs, skin, gonads, and eyes. In utero exposure of the fetus is also considered. New data and modeling techniques available since publication of the Reactor Safety Study (WASH 1400, 1975) were used along with data cited in the Study to develop improved health-risk models for morbidity and mortality. The new models are applicable to a broader range of accident scenarios, provide a more detailed treatment of dose protraction effects, and include morbidity effects not considered in the Reactor Safety Study. 115 references, 20 figures, 19 tables

  11. Occurence of larval Culicidae (Diptera in water retained in Aquascypha hydrophora (Fungus: Stereaceae in Central Amazônia, Brazil

    Directory of Open Access Journals (Sweden)

    Ruth LM Ferreira

    2001-11-01

    Full Text Available The community structure of insects, especially mosquito larvae, in water held in the fungus Aquascypha hydrophora (Berk. Reid (Stereaceae is reported. The study was done in the Adolpho Ducke Forest Reserve, 26 km east of Manaus, AM, Brazil, from September 1998 through November 1999. The most abundant entomofauna were immature Culicidae (n = 121 91.7%, followed by adult Dytiscidae (n = 3 2.3%, immature Chironomidae (n = 5 3.8% and immature Tipulidae (n = 3 2.3%. Culicidae associated with A. hydrophora comprised species of the subfamilies Anophelinae and Culicinae.

  12. Drivers of variability in water use of two co-occurring species in a subalpine forest in Jiuzhaigou Valley, Southwest of China

    Science.gov (United States)

    Yan, C.; Zhao, W.; Wang, Y.; Zhang, Q.; Qiu, G. Y.

    2016-12-01

    Co-occur species with different sensitivity to soil water may be particularly useful in evaluating water use by different forest stands as well as the response of species distribution, forest structure and stand composition to soil water availability in water-limited area. To clarify the species-specific water use strategy and provide insights into the possible succession trend, variations in sap flow and environmental conditions were investigated for two co-occur species (Betula albo-sinensis and Pinus tabulaeformis) in a mixed forest in Jiuzhaigou Valley in 2014. Sap flow was measured by Granier-type thermal dissipation probes and soil water content was measured by time-domain reflectometry probes for a successive period. Pinus tabulaeformis and Betua albo-sinensis species showed different responses to meteorological factors under different soil water conditions. Despite that whole tree water use was much higher for Pinus tabulaeformis due to greater sapwood area, sap flux density of the other co-occurring species Betua albo-sinensis was higher throughout the growing season. Normalized sap flux density (Fd) could be mostly well fitted to solar radiation (Rs), vapor pressure deficit (VPD), or the variable of transpiration (VT) by the exponential saturation function. Much better fitted curves were found for Fd -VPD and Fd - VT datasets than Fd - Rs datasets. For most datasets, normalized Fd increased rapidly when the environmental factors were below their threshold values, but reached an asymptote thereafter. Based on the species' differences in fitting parameters and the average maximum sap flow level under different soil water conditions, it was concluded that Pinus tabulaeformis was sensitive to soil water conditions and tolerant of low soil water availability, while Betua albo-sinensis was insensitive to soil moisture and needed to access to similarly high amount of soil water in the growing season after leaf expansion. These results indicated possible

  13. Ground-Penetrating-Radar Profiles of Interior Alaska Highways: Interpretation of Stratified Fill, Frost Depths, Water Table, and Thaw Settlement over Ice-Rich Permafrost

    Science.gov (United States)

    2016-08-01

    along either massive ice surfaces or within sections of segregated ice. The uninsulated ice surface at Tok in Figure 17B is irregular. All of the...ER D C/ CR RE L TR -1 6- 14 ERDC’s Center-Directed Research Program Ground -Penetrating-Radar Profiles of Interior Alaska Highways...August 2016 Ground -Penetrating-Radar Profiles of Interior Alaska Highways Interpretation of Stratified Fill, Frost Depths, Water Table, and Thaw

  14. Accounting for intracell flow in models with emphasis on water table recharge and stream-aquifer interaction: 1. Problems and concepts

    Science.gov (United States)

    Jorgensen, Donald G.; Signor, Donald C.; Imes, Jeffrey L.

    1989-01-01

    Intracell flow is important in modeling cells that contain both sources and sinks. Special attention is needed if recharge through the water table is a source. One method of modeling multiple sources and sinks is to determine the net recharge per cell. For example, for a model cell containing both a sink and recharge through the water table, the amount of recharge should be reduced by the ratio of the area of influence of the sink within the cell to the area of the cell. The reduction is the intercepted portion of the recharge. In a multilayer model this amount is further reduced by a proportion factor, which is a function of the depth of the flow lines from the water table boundary to the internal sink. A gaining section of a stream is a typical sink. The aquifer contribution to a gaining stream can be conceptualized as having two parts; the first part is the intercepted lateral flow from the water table and the second is the flow across the streambed due to differences in head between the water level in the stream and the aquifer below. The amount intercepted is a function of the geometry of the cell, but the amount due to difference in head across the stream bed is largely independent of cell geometry. A discharging well can intercept recharge through the water table within a model cell. The net recharge to the cell would be reduced in proportion to the area of influence of the well within the cell. The area of influence generally changes with time. Thus the amount of intercepted recharge and net recharge may not be constant with time. During periods when the well is not discharging there will be no intercepted recharge even though the area of influence from previous pumping may still exist. The reduction of net recharge per cell due to internal interception of flow will result in a model-calculated mass balance less than the prototype. Additionally the “effective transmissivity” along the intercell flow paths may be altered when flow paths are occupied by

  15. Environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks, New Jersey Coastal Plain, USA: migration to the water table.

    Science.gov (United States)

    Szabo, Zoltan; Jacobsen, Eric; Kraemer, Thomas F; Parsa, Bahman

    2010-01-01

    Fate of radium (Ra) in liquid regeneration brine wastes from water softeners disposed to septic tanks in the New Jersey Coastal Plain was studied. Before treatment, combined Ra ((226)Ra plus (228)Ra) concentrations (maximum, 1.54 Bq L(-1)) exceeded the 0.185 Bq L(-1) Maximum Contaminant Level in 4 of 10 studied domestic-well waters (median pH, 4.90). At the water table downgradient from leachfields, combined Ra concentrations were low (commonly 5.3, indicating sequestration; when pH was septic-tank effluents (maximum, 0.243 Bq L(-1))), indicating Ra mobilization from leachfield sediments. Confidence in quantification of Ra mass balance was reduced by study design limitations, including synoptic sampling of effluents and ground waters, and large uncertainties associated with analytical methods. The trend of Ra mobilization in acidic environments does match observations from regional water-quality assessments.

  16. Synthesis of the IRSN report on the topic of water way answers to implement in case of accident with core meltdown occurring on operating pressurized water nuclear reactors

    International Nuclear Information System (INIS)

    2009-06-01

    This report briefly discusses the efficiency of technical measures adopted for the implementation of water ways as answers to an accident with core meltdown in operating pressurized water nuclear reactors. While mentioning the importance of the hydro-geological characteristics of the various sites, the IRSN asks EDF to plan and implement means to prevent any rejection through water ways for some of these sites, to investigate the possibility of building a geotechnical enclosure, to define a storing-control-treatment-rejection chain which would guarantee an efficient management of the water to be pumped, to study retention phenomena for strontium and caesium isotopes in sands and gravels

  17. A Modern Periodic Table.

    Science.gov (United States)

    Herrenden-Harker, B. D.

    1997-01-01

    Presents a modern Periodic Table based on the electron distribution in the outermost shell and the order of filling of the sublevels within the shells. Enables a student to read off directly the electronic configuration of the element and the order in which filling occurs. (JRH)

  18. Molecular mechanisms of water table lowering and nitrogen deposition in affecting greenhouse gas emissions from a Tibetan alpine wetland.

    Science.gov (United States)

    Wang, Hao; Yu, Lingfei; Zhang, Zhenhua; Liu, Wei; Chen, Litong; Cao, Guangmin; Yue, Haowei; Zhou, Jizhong; Yang, Yunfeng; Tang, Yanhong; He, Jin-Sheng

    2017-02-01

    Rapid climate change and intensified human activities have resulted in water table lowering (WTL) and enhanced nitrogen (N) deposition in Tibetan alpine wetlands. These changes may alter the magnitude and direction of greenhouse gas (GHG) emissions, affecting the climate impact of these fragile ecosystems. We conducted a mesocosm experiment combined with a metagenomics approach (GeoChip 5.0) to elucidate the effects of WTL (-20 cm relative to control) and N deposition (30 kg N ha -1  yr -1 ) on carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) fluxes as well as the underlying mechanisms. Our results showed that WTL reduced CH 4 emissions by 57.4% averaged over three growing seasons compared with no-WTL plots, but had no significant effect on net CO 2 uptake or N 2 O flux. N deposition increased net CO 2 uptake by 25.2% in comparison with no-N deposition plots and turned the mesocosms from N 2 O sinks to N 2 O sources, but had little influence on CH 4 emissions. The interactions between WTL and N deposition were not detected in all GHG emissions. As a result, WTL and N deposition both reduced the global warming potential (GWP) of growing season GHG budgets on a 100-year time horizon, but via different mechanisms. WTL reduced GWP from 337.3 to -480.1 g CO 2 -eq m -2 mostly because of decreased CH 4 emissions, while N deposition reduced GWP from 21.0 to -163.8 g CO 2 -eq m -2 , mainly owing to increased net CO 2 uptake. GeoChip analysis revealed that decreased CH 4 production potential, rather than increased CH 4 oxidation potential, may lead to the reduction in net CH 4 emissions, and decreased nitrification potential and increased denitrification potential affected N 2 O fluxes under WTL conditions. Our study highlights the importance of microbial mechanisms in regulating ecosystem-scale GHG responses to environmental changes. © 2016 John Wiley & Sons Ltd.

  19. Scanning table

    CERN Multimedia

    1960-01-01

    Before the invention of wire chambers, particles tracks were analysed on scanning tables like this one. Today, the process is electronic and much faster. Bubble chamber film - currently available - (links can be found below) was used for this analysis of the particle tracks.

  20. Long-term rise of the Water Table in the Northeast US: Climate Variability, Land-Use Change, or Angry Beavers?

    Science.gov (United States)

    Boutt, D. F.

    2011-12-01

    The scientific evidence that humans are directly influencing the Earth's natural climate is increasingly compelling. Numerous studies suggest that climate change will lead to changes in the seasonality of surface water availability thereby increasing the need for groundwater development to offset those shortages. Research suggests that the Northeast region of the U.S. is experiencing significant changes to its' natural climate and hydrologic systems. Previous analysis of a long-term regional compilation of the water table response to the last 60 years of climate variability in New England documented a wide range of variability. The investigation evaluated the physical mechanisms, natural variability and response of aquifers in New England using 100 long term groundwater monitoring stations with 20 or more years of data coupled with 67 stream gages, 75 precipitation stations, and 43 temperature stations. Groundwater trends were calculated as normalized anomalies and analyzed with respect to regional compiled precipitation, temperature, and streamflow anomalies to understand the sensitivity of the aquifer systems to change. Interestingly, a trend and regression analysis demonstrate that water level fluctuations are producing statistically significant results with increasing water levels over at least the past thirty years at most (80 out of 100) well sites. In this contribution we investigate the causal mechanisms behind the observed ground water level trends using site-by-site land-use change assessments, cluster analysis, and spatial analysis of beaver populations (a possible proxy for beaver activity). Regionally, average annual precipitation has been slightly increasing since 1900, with 95% of the stations having statistically significant positive trends. Despite this, no correlation is observed between the magnitude of the annual precipitation trends and the magnitude of the groundwater level changes. Land-use change throughout the region has primarily taken

  1. Stochastic simulation of time-series models combined with geostatistics to predict water-table scenarios in a Guarani Aquifer System outcrop area, Brazil

    Science.gov (United States)

    Manzione, Rodrigo L.; Wendland, Edson; Tanikawa, Diego H.

    2012-11-01

    Stochastic methods based on time-series modeling combined with geostatistics can be useful tools to describe the variability of water-table levels in time and space and to account for uncertainty. Monitoring water-level networks can give information about the dynamic of the aquifer domain in both dimensions. Time-series modeling is an elegant way to treat monitoring data without the complexity of physical mechanistic models. Time-series model predictions can be interpolated spatially, with the spatial differences in water-table dynamics determined by the spatial variation in the system properties and the temporal variation driven by the dynamics of the inputs into the system. An integration of stochastic methods is presented, based on time-series modeling and geostatistics as a framework to predict water levels for decision making in groundwater management and land-use planning. The methodology is applied in a case study in a Guarani Aquifer System (GAS) outcrop area located in the southeastern part of Brazil. Communication of results in a clear and understandable form, via simulated scenarios, is discussed as an alternative, when translating scientific knowledge into applications of stochastic hydrogeology in large aquifers with limited monitoring network coverage like the GAS.

  2. Effects of leaf area index on the coupling between water table, land surface energy fluxes, and planetary boundary layer at the regional scale

    Science.gov (United States)

    Lu, Y.; Rihani, J.; Langensiepen, M.; Simmer, C.

    2013-12-01

    Vegetation plays an important role in the exchange of moisture and energy at the land surface. Previous studies indicate that vegetation increases the complexity of the feedbacks between the atmosphere and subsurface through processes such as interception, root water uptake, leaf surface evaporation, and transpiration. Vegetation cover can affect not only the interaction between water table depth and energy fluxes, but also the development of the planetary boundary layer. Leaf Area Index (LAI) is shown to be a major factor influencing these interactions. In this work, we investigate the sensitivity of water table, surface energy fluxes, and atmospheric boundary layer interactions to LAI as a model input. We particularly focus on the role LAI plays on the location and extent of transition zones of strongest coupling and how this role changes over seasonal timescales for a real catchment. The Terrestrial System Modelling Platform (TerrSysMP), developed within the Transregional Collaborative Research Centre 32 (TR32), is used in this study. TerrSysMP consists of the variably saturated groundwater model ParFlow, the land surface model Community Land Model (CLM), and the regional climate and weather forecast model COSMO (COnsortium for Small-scale Modeling). The sensitivity analysis is performed over a range of LAI values for different vegetation types as extracted from the Moderate Resolution Imaging Spectroradiometer (MODIS) dataset for the Rur catchment in Germany. In the first part of this work, effects of vegetation structure on land surface energy fluxes and their connection to water table dynamics are studied using the stand-alone CLM and the coupled subsurface-surface components of TerrSysMP (ParFlow-CLM), respectively. The interconnection between LAI and transition zones of strongest coupling are investigated and analyzed through a subsequent set of subsurface-surface-atmosphere coupled simulations implementing the full TerrSysMP model system.

  3. A Country-Specific Water Consumption Inventory Considering International Trade in Asian Countries Using a Multi-Regional Input-Output Table

    Directory of Open Access Journals (Sweden)

    Yuya Ono

    2017-08-01

    Full Text Available Interest in the impacts of water use in the life cycle of products and services are increasing among various stakeholders. The water footprint is a tool to identify critical and effective points for reducing the impact of water use through the entire life cycle of products, services, and organizations. The purpose of this study was to develop a water consumption inventory database that focused on identifying of Asian water consumption using an input-output (IO framework. An Asia International Input-Output table (AIIO was applied in this study. The amount of water consumption required for agricultural products was estimated by modeling; for other sectors it was estimated from statistical reports. The intensities of direct water consumption in each sector were calculated by dividing the amount of water consumption by the domestic production. Based on the IO analysis using Leontief’s inverse matrix, the intensities of water consumption from cradle to gate were estimated for all goods and services. There was high intensity of water consumption in the primary industry sectors, together with a high dependency on rainwater as an input water source. The water consumption intensities generally showed a larger reduction in secondary sectors, in comparison with the tertiary sectors, due to the use of recycled water. There were differences between this study and previous studies due to the use of site-specific production data and the temporal resolution of crop production. By considering site-specific conditions, it is expected that the dataset developed here can be used for estimating the water footprint of products, services, and organizations in nine countries (Japan, South Korea, China, Taiwan, Thailand, the Philippines, Malaysia, Singapore, Indonesia, and USA.

  4. Litter type affects the activity of aerobic decomposers in a boreal peatland more than site nutrient and water table regimes

    Directory of Open Access Journals (Sweden)

    P. Straková

    2011-09-01

    Full Text Available Peatlands are carbon (C storage ecosystems sustained by a high water table (WT. High WT creates anoxic conditions that suppress the activity of aerobic decomposers and provide conditions for peat accumulation. Peatland function can be dramatically affected by WT drawdown caused by climate and/or land-use change. Aerobic decomposers are directly affected by WT drawdown through environmental factors such as increased oxygenation and nutrient availability. Additionally, they are indirectly affected via changes in plant community composition and litter quality. We studied the relative importance of direct and indirect effects of WT drawdown on aerobic decomposer activity in plant litter at two stages of decomposition (incubated in the field for 1 or 2 years. We did this by profiling 11 extracellular enzymes involved in the mineralization of organic C, nitrogen (N, phosphorus (P and sulphur. Our study sites represented a three-stage chronosequence from pristine to short-term (years and long-term (decades WT drawdown conditions under two nutrient regimes (bog and fen. The litter types included reflected the prevalent vegetation: Sphagnum mosses, graminoids, shrubs and trees.

    Litter type was the main factor shaping microbial activity patterns and explained about 30 % of the variation in enzyme activities and activity allocation. Overall, enzyme activities were higher in vascular plant litters compared to Sphagnum litters, and the allocation of enzyme activities towards C or nutrient acquisition was related to the initial litter quality (chemical composition. Direct effects of WT regime, site nutrient regime and litter decomposition stage (length of incubation period summed to only about 40 % of the litter type effect. WT regime alone explained about 5 % of the variation in enzyme activities and activity allocation. Generally, enzyme activity increased following the long-term WT drawdown and the activity allocation turned from P

  5. Litter type affects the activity of aerobic decomposers in a boreal peatland more than site nutrient and water table regimes

    Science.gov (United States)

    Straková, P.; Niemi, R. M.; Freeman, C.; Peltoniemi, K.; Toberman, H.; Heiskanen, I.; Fritze, H.; Laiho, R.

    2011-09-01

    Peatlands are carbon (C) storage ecosystems sustained by a high water table (WT). High WT creates anoxic conditions that suppress the activity of aerobic decomposers and provide conditions for peat accumulation. Peatland function can be dramatically affected by WT drawdown caused by climate and/or land-use change. Aerobic decomposers are directly affected by WT drawdown through environmental factors such as increased oxygenation and nutrient availability. Additionally, they are indirectly affected via changes in plant community composition and litter quality. We studied the relative importance of direct and indirect effects of WT drawdown on aerobic decomposer activity in plant litter at two stages of decomposition (incubated in the field for 1 or 2 years). We did this by profiling 11 extracellular enzymes involved in the mineralization of organic C, nitrogen (N), phosphorus (P) and sulphur. Our study sites represented a three-stage chronosequence from pristine to short-term (years) and long-term (decades) WT drawdown conditions under two nutrient regimes (bog and fen). The litter types included reflected the prevalent vegetation: Sphagnum mosses, graminoids, shrubs and trees. Litter type was the main factor shaping microbial activity patterns and explained about 30 % of the variation in enzyme activities and activity allocation. Overall, enzyme activities were higher in vascular plant litters compared to Sphagnum litters, and the allocation of enzyme activities towards C or nutrient acquisition was related to the initial litter quality (chemical composition). Direct effects of WT regime, site nutrient regime and litter decomposition stage (length of incubation period) summed to only about 40 % of the litter type effect. WT regime alone explained about 5 % of the variation in enzyme activities and activity allocation. Generally, enzyme activity increased following the long-term WT drawdown and the activity allocation turned from P and N acquisition towards C

  6. Water-table and potentiometric-surface altitudes in the upper glacial, Magothy, and Lloyd aquifers of Long Island, New York, April–May 2016

    Science.gov (United States)

    Como, Michael D.; Finkelstein, Jason S.; Rivera, Simonette L.; Monti, Jack; Busciolano, Ronald J.

    2018-06-06

    The U.S. Geological Survey, in cooperation with State and local agencies, systematically collects groundwater data at varying measurement frequencies to monitor the hydrologic conditions on Long Island, New York. Each year during April and May, the U.S. Geological Survey completes a synoptic survey of water levels to define the spatial distribution of the water table and potentiometric surfaces within the three main water-bearing units underlying Long Island—the upper glacial, Magothy, and Lloyd aquifers—and the hydraulically connected Jameco and North Shore aquifers. These data and the maps constructed from them are commonly used in studies of the hydrology of Long Island and are used by water managers and suppliers for aquifer management and planning purposes.Water-level measurements made in 424 monitoring wells (observation and supply wells), 13 streamgages, and 2 lake gages across Long Island during April–May 2016 were used to prepare the maps in this report. Groundwater measurements were made by the wetted-tape or electric-tape method to the nearest hundredth of a foot. Contours of water-table and potentiometric-surface altitudes were created using the groundwater measurements. The water-table contours were interpreted using water-level data collected from 275 observation wells and 1 supply well screened in the upper glacial aquifer and the shallow Magothy aquifer and 13 streamgages and 2 lake gages. The potentiometric-surface contours of the Magothy aquifer were interpreted from measurements at 88 wells (61 observation wells and 27 supply wells) screened in the middle to deep Magothy aquifer and the contiguous and hydraulically connected Jameco aquifer. The potentiometric-surface contours of the Lloyd aquifer were interpreted from measurements at 60 wells (55 observation wells and 5 supply wells) screened in the Lloyd aquifer and the contiguous and hydraulically connected North Shore aquifer. Many of the supply wells are in continuous operation and

  7. Depth dependent microbial carbon use efficiency in the capillary fringe as affected by water table fluctuations in a column incubation experiment

    Science.gov (United States)

    Pronk, G. J.; Mellage, A.; Milojevic, T.; Smeaton, C. M.; Rezanezhad, F.; Van Cappellen, P.

    2017-12-01

    Microbial growth and turnover of soil organic carbon (SOC) depend on the availability of electron donors and acceptors. The steep geochemical gradients in the capillary fringe between the saturated and unsaturated zones provide hotspots of soil microbial activity. Water table fluctuations and the associated drying and wetting cycles within these zones have been observed to lead to enhanced turnover of SOC and adaptation of the local microbial communities. To improve our understanding of SOC degradation under changing moisture conditions, we carried out an automated soil column experiment with integrated of hydro-bio-geophysical monitoring under both constant and oscillating water table conditions. An artificial soil mixture composed of quartz sand, montmorillonite, goethite and humus was used to provide a well-defined system. This material was inoculated with a microbial community extracted from a forested riparian zone. The soils were packed into 6 columns (60 cm length and 7.5 cm inner diameter) to a height of 45 cm; and three replicate columns were incubated under constant water table while another three were saturated and drained monthly. The initial soil development, carbon cycling and microbial community development were then characterized during 10 months of incubation. This system provides an ideal artificial gradient from the saturated to the unsaturated zone to study soil development from initially homogeneous materials and the same microbial community composition under controlled conditions. Depth profiles of SOC and microbial biomass after 329 days of incubation showed a depletion of carbon in the transition drying and wetting zone that was not associated with higher accumulation of microbial biomass, indicating a lower carbon use efficiency of the microbial community established within the water table fluctuation zone. This was supported by a higher ATP to microbial biomass carbon ratio within the same zone. The findings from this study highlight the

  8. Occurence of antibiotic compounds found in the water column and bottom sediments from a stream receiving two waste water treatment plant effluents in northern New Jersey, 2008

    Science.gov (United States)

    Gibs, Jacob; Heckathorn, Heather A.; Meyer, Michael T.; Klapinski, Frank R.; Alebus, Marzooq; Lippincott, Robert

    2013-01-01

    An urban watershed in northern New Jersey was studied to determine the presence of four classes of antibiotic compounds (macrolides, fluoroquinolones, sulfonamides, and tetracyclines) and six degradates in the water column and bottom sediments upstream and downstream from the discharges of two wastewater treatment plants (WWTPs) and a drinking-water intake (DWI). Many antibiotic compounds in the four classes not removed by conventional WWTPs enter receiving waters and partition to stream sediments. Samples were collected at nine sampling locations on 2 days in September 2008. Two of the nine sampling locations were background sites upstream from two WWTP discharges on Hohokus Brook. Another background site was located upstream from a DWI on the Saddle River above the confluence with Hohokus Brook. Because there is a weir downstream of the confluence of Hohokus Brook and Saddle River, the DWI receives water from Hohokus Brook at low stream flows. Eight antibiotic compounds (azithromycin (maximum concentration 0.24 μg/L), ciprofloxacin (0.08 μg/L), enrofloxacin (0.015 μg/L), erythromycin (0.024 μg/L), ofloxacin (0.92 μg/L), sulfamethazine (0.018 μg/L), sulfamethoxazole (0.25 μg/L), and trimethoprim (0.14 μg/L)) and a degradate (erythromycin-H2O (0.84 μg/L)) were detected in the water samples from the sites downstream from the WWTP discharges. The concentrations of six of the eight detected compounds and the detected degradate compound decreased with increasing distance downstream from the WWTP discharges. Azithromycin, ciprofloxacin, ofloxacin, and trimethoprim were detected in stream-bottom sediments. The concentrations of three of the four compounds detected in sediments were highest at a sampling site located downstream from the WWTP discharges. Trimethoprim was detected in the sediments from a background site. Pseudo-partition coefficients normalized for streambed sediment organic carbon concentration were calculated for azithromycin, ciprofloxacin, and

  9. Naturally occurring radioactive elements, arsenic and other metals in drinking water from private wells; Naturligt radioaktiva aemnen, arsenik och andra metaller i dricksvatten fraan enskilda brunnar

    Energy Technology Data Exchange (ETDEWEB)

    Ek, Britt-Marie; Thunholm, Bo (Geological Survey of Sweden (SGU), Uppsala (SE)); Oestergren, Inger; Falk, Rolf; Mjoenes, Lars (Swedish Radiation Protection Authority, Stockholm (Sweden))

    2008-04-15

    Approximately 50% of all drinking water is extracted from groundwater. For private supply of drinking water almost 100% emanates from groundwater. For approximately 1.2 of the 9 million Swedish citizens, private wells are the primary water source where 700 000 get their water from wells drilled in the bedrock. Radioactive elements and metals that occur naturally in the bedrock can be found in the well water. The radioactive elements include radon-222 (222Rn), uranium (U), radium-226 (226Ra) as well as polonium-210 (210Po) and lead-210 (210Pb), which are long-lived progeny of radon. In 2001 SGU and SSI initiated a collaboration to investigate the occurrence of radioactive elements and metals in water from private wells. Data sampling and analysis was completed in 2006. The aim of the project was to map the occurrence of radioactive elements in drinking water from private wells and to estimate their respective dose contribution. Another aim was to map metals and other elements in the water, to study temporal variations and possible co-variations between analysed elements. Sampling was conducted in a random fashion throughout the country. However, in regions where bedrock and soils are known to show enhanced concentrations of radioactive elements and arsenic the sampling density was increased. The analyses comprises: total beta activity, total alpha activity, radium-226, radon-222, uranium, aluminium, chloride, calcium, vanadium, chromium, iron, manganese, cobalt, nickel, copper, zink, arsenic, strontium, molybdenum, cadmium, barium, lead, thorium, boron, sodium, manganese, potassium, silica, alkalinity, sulfate, fluoride, phosphate, nitrate, pH and electric conductivity. In a few cases chemistry analyses of polonium-210 and lead-210 have been done. It was observed that the south-western part of Sweden, with exception for granite areas in the county of Bohuslaen, has relatively low concentrations of natural radioactive elements in the drinking water. The occurrence of

  10. Physico-chemical characteristics of the ground water table after monsoon: a case study at central Travancore in Kerala

    Directory of Open Access Journals (Sweden)

    Sankar S Vishnu

    2014-05-01

    Full Text Available Water quality plays an important role in maintaining plant and animal life. Lack of good quality drinking water and water for sanitation cause health problems. Water quality characteristics arise from a group of physical, chemical and biological factors. The dynamic balance of the aquatic system can be destroyed by human activities resulting in water pollution.Well water has traditionally considered as a safe resource of water for consumption without treatment and extensively used for individual water supply in rural and many urban areas.In this paper a preliminary analysis is done to explore the water quality of selected wells in order to correlate the effect of pollution on water quality at these locations. Water samples are collected from different regions of Vazhappally area located on central travancore of Kerala. These sites are important because people depend only on well water for drinking purpose. The samples are collected from ten locations and analyzed for chemical parameters such as pH, conductivity, salinity, turbidity, acidity, alkainity, hardness, total phosphates, dissolved oxygen, biological oxygen demand, total dissolved solids and Iron content. Samples are also analysed for coliform bacteria which cause pathogenic diseases. Remarkable differences are observed mainly in biological oxygen demand, acidity and hardness. Finally, an attempt has been done to correlate the observed chemical parameters and the waterquality standards. DOI: http://dx.doi.org/10.3126/ije.v3i2.10501 International Journal of the Environment Vol.3(2 2014: 20-27

  11. Modeling the potential impacts of climate change on the water table level of selected forested wetlands in the southeastern United States

    Directory of Open Access Journals (Sweden)

    J. Zhu

    2017-12-01

    Full Text Available The southeastern United States hosts extensive forested wetlands, providing ecosystem services including carbon sequestration, water quality improvement, groundwater recharge, and wildlife habitat. However, these wetland ecosystems are dependent on local climate and hydrology, and are therefore at risk due to climate and land use change. This study develops site-specific empirical hydrologic models for five forested wetlands with different characteristics by analyzing long-term observed meteorological and hydrological data. These wetlands represent typical cypress ponds/swamps, Carolina bays, pine flatwoods, drained pocosins, and natural bottomland hardwood ecosystems. The validated empirical models are then applied at each wetland to predict future water table changes using climate projections from 20 general circulation models (GCMs participating in Coupled Model Inter-comparison Project 5 (CMIP5 under the Representative Concentration Pathways (RCPs 4.5 and 8.5 scenarios. We show that combined future changes in precipitation and potential evapotranspiration would significantly alter wetland hydrology including groundwater dynamics by the end of the 21st century. Compared to the historical period, all five wetlands are predicted to become drier over time. The mean water table depth is predicted to drop by 4 to 22 cm in response to the decrease in water availability (i.e., precipitation minus potential evapotranspiration by the year 2100. Among the five examined wetlands, the depressional wetland in hot and humid Florida appears to be most vulnerable to future climate change. This study provides quantitative information on the potential magnitude of wetland hydrological response to future climate change in typical forested wetlands in the southeastern US.

  12. Modeling the potential impacts of climate change on the water table level of selected forested wetlands in the southeastern United States

    Science.gov (United States)

    Zhu, Jie; Sun, Ge; Li, Wenhong; Zhang, Yu; Miao, Guofang; Noormets, Asko; McNulty, Steve G.; King, John S.; Kumar, Mukesh; Wang, Xuan

    2017-12-01

    The southeastern United States hosts extensive forested wetlands, providing ecosystem services including carbon sequestration, water quality improvement, groundwater recharge, and wildlife habitat. However, these wetland ecosystems are dependent on local climate and hydrology, and are therefore at risk due to climate and land use change. This study develops site-specific empirical hydrologic models for five forested wetlands with different characteristics by analyzing long-term observed meteorological and hydrological data. These wetlands represent typical cypress ponds/swamps, Carolina bays, pine flatwoods, drained pocosins, and natural bottomland hardwood ecosystems. The validated empirical models are then applied at each wetland to predict future water table changes using climate projections from 20 general circulation models (GCMs) participating in Coupled Model Inter-comparison Project 5 (CMIP5) under the Representative Concentration Pathways (RCPs) 4.5 and 8.5 scenarios. We show that combined future changes in precipitation and potential evapotranspiration would significantly alter wetland hydrology including groundwater dynamics by the end of the 21st century. Compared to the historical period, all five wetlands are predicted to become drier over time. The mean water table depth is predicted to drop by 4 to 22 cm in response to the decrease in water availability (i.e., precipitation minus potential evapotranspiration) by the year 2100. Among the five examined wetlands, the depressional wetland in hot and humid Florida appears to be most vulnerable to future climate change. This study provides quantitative information on the potential magnitude of wetland hydrological response to future climate change in typical forested wetlands in the southeastern US.

  13. Determining the critical relative humidity at which the glassy to rubbery transition occurs in polydextrose using an automatic water vapor sorption instrument.

    Science.gov (United States)

    Yuan, Xiaoda; Carter, Brady P; Schmidt, Shelly J

    2011-01-01

    Similar to an increase in temperature at constant moisture content, water vapor sorption by an amorphous glassy material at constant temperature causes the material to transition into the rubbery state. However, comparatively little research has investigated the measurement of the critical relative humidity (RHc) at which the glass transition occurs at constant temperature. Thus, the central objective of this study was to investigate the relationship between the glass transition temperature (Tg), determined using thermal methods, and the RHc obtained using an automatic water vapor sorption instrument. Dynamic dewpoint isotherms were obtained for amorphous polydextrose from 15 to 40 °C. RHc was determined using an optimized 2nd-derivative method; however, 2 simpler RHc determination methods were also tested as a secondary objective. No statistical difference was found between the 3 RHc methods. Differential scanning calorimetry (DSC) Tg values were determined using polydextrose equilibrated from 11.3% to 57.6% RH. Both standard DSC and modulated DSC (MDSC) methods were employed, since some of the polydextrose thermograms exhibited a physical aging peak. Thus, a tertiary objective was to compare Tg values obtained using 3 different methods (DSC first scan, DSC rescan, and MDSC), to determine which method(s) yielded the most accurate Tg values. In general, onset and midpoint DSC first scan and MDSC Tg values were similar, whereas onset and midpoint DSC rescan values were different. State diagrams of RHc and experimental temperature and Tg and %RH were compared. These state diagrams, though obtained via very different methods, showed relatively good agreement, confirming our hypothesis that water vapor sorption isotherms can be used to directly detect the glassy to rubbery transition. Practical Application: The food polymer science (FPS) approach, pioneered by Slade and Levine, is being successfully applied in the food industry for understanding, improving, and

  14. Water-table altitude of the unconfined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

    Data.gov (United States)

    Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  15. Three-dimensional hydrogeological modeling to assess the elevated-water-table technique for controlling acid generation from an abandoned tailings site in Quebec, Canada

    Science.gov (United States)

    Ethier, Marie-Pier; Bussière, Bruno; Broda, Stefan; Aubertin, Michel

    2018-01-01

    The Manitou Mine sulphidic-tailings storage facility No. 2, near Val D'Or, Canada, was reclaimed in 2009 by elevating the water table and applying a monolayer cover made of tailings from nearby Goldex Mine. Previous studies showed that production of acid mine drainage can be controlled by lowering the oxygen flux through Manitou tailings with a water table maintained at the interface between the cover and reactive tailings. Simulations of different scenarios were performed using numerical hydrogeological modeling to evaluate the capacity of the reclamation works to maintain the phreatic surface at this interface. A large-scale numerical model was constructed and calibrated using 3 years of field measurements. This model reproduced the field measurements, including the existence of a western zone on the site where the phreatic level targeted is not always met during the summer. A sensitivity analysis was performed to assess the response of the model to varying saturated hydraulic conductivities, porosities, and grain-size distributions. Higher variations of the hydraulic heads, with respect to the calibrated scenario results, were observed when simulating a looser or coarser cover material. Long-term responses were simulated using: the normal climatic data, data for a normal climate with a 2-month dry spell, and a simplified climate-change case. Environmental quality targets were reached less frequently during summer for the dry spell simulation as well as for the simplified climate-change scenario. This study illustrates how numerical simulations can be used as a key tool to assess the eventual performance of various mine-site reclamation scenarios.

  16. Scots pine (Pinus sylvestris L.) based reconstruction of 130 years of water table fluctuations in a peatland and its relevance for moisture variability assessments

    Science.gov (United States)

    Tamkevičiūtė, Marija; Edvardsson, Johannes; Pukienė, Rūtilė; Taminskas, Julius; Stoffel, Markus; Corona, Christophe; Kibirkštis, Gintautas

    2018-03-01

    Continuous water-table (WT) measurements from peatlands are scarce and - if existing at all -very short. Consequently, proxy indicators are critically needed to simulate hydrological changes in peatlands over longer time periods. In this study, we demonstrate that tree-ring width (TRW) records of Scots pine (Pinus sylvestris L.) growing in the Čepkeliai peatland (southern Lithuania) can be used as a proxy to reconstruct hydrological variability in a raised bog environment. A two-step modelling procedure was applied to extend existing measurements and to develop a new and longer peatland WT time series. To this end, we used instrumental WT measurements extending back to 2002, meteorological records, a P-PET (difference between precipitation and potential evapotranspiration) series covering the period 1935-2014, so as to construct a tree-ring based time series of WT fluctuations at the site for the period 1870-2014. Strongest correlations were obtained between average annual WT measured at the bog margin and total P-PET over 7 years (r = 0.923, p runoff since CE 1812 (r = 0.39, p < 0.00001, 1870-2014). We conclude that peatlands can act both as sinks and sources of greenhouse gases in case that hydrological conditions change, but that hydrological lags and complex feedbacks still hamper our understanding of several processes affecting the hydrology and carbon budget in peatlands. We therefore call for the development of further proxy records of water-table variability in peatlands to improve our understanding of peatland responses to climatic changes.

  17. Plant species distribution in relation to water-table depth and soil redox potential in montane riparian meadows

    Science.gov (United States)

    Kathleen A. Dwire; J. Boone Kauffman; John E. Baham

    2006-01-01

    The distribution of riparian plant species is largely driven by hydrologic and soil variables, and riparian plant communities frequently occur in relatively distinct zones along streamside elevational and soil textural gradients. In two montane meadows in northeast Oregon, USA, we examined plant species distribution in three riparian plant communities¡ªdefined as wet,...

  18. Physiological and morphological effects of high water tables on early growth of giant reed (Arundo donax), elephant grass (Pennisetum purpureum), energycane and sugarcane (Saccharum spp.)

    Energy Technology Data Exchange (ETDEWEB)

    Jennewein, Stephen Peter [Univ. of Florida, Gainesville, FL (United States)

    2013-01-01

    Here, an increasing demand for renewable energy sources has spurred interest in high-biomass crops used for energy production. Species potentially well-suited for biofuel production in the seasonally wet organic Everglades Agricultural Area (EAA) of Florida include giant reed (Arundo donax), elephant grass (Pennisetum Purpureum), energycane (Saccharum spp.), and sugarcane (Saccharum spp.). The objectives in this study were to evaluate the role of fluctuating water tables on the morphology, physiology, and early season growth of these four genotypes. The candidate genotypes were grown in a greenhouse under three water table depths, defined by distance of the water table from the soil surface: two constant water tables (-16 cm and -40 cm) along with a flood cycle (2 weeks of flood to the soil level followed by 2 weeks at -40 cm from the soil level). The genotypes included CP 89-2143 (sugarcane), L 79-1002 (energycane), Merkeron (elephant grass), and wild type (giant reed). The experiment was repeated for plant cane, first ratoon, and successive plant cane crop cycles. Reductions in dry matter yield were observed among genotypes subjected to the -40 cm drained, periodically flooded (40F) water table relative to the -40 cm constant (40C) or -16 cm constant (16C). Plant cane dry weights were reduced by 37% in giant reed, 52% in elephant grass, 42% in energycane, and 34% in sugarcane in the 40F compared to 40C water table treatments. Similarly, in the first ratoon crop dry weights were reduced by 29% in giant reed, 42% in elephant grass, 27% in energycane, and 62% in sugarcane. In plant cane and successive plant cane, average total dry weight was greatest for elephant grass whereas ratoon total dry weight was greatest for energycane. Genotype had more pronounced effects on physiological attributes than water table including the highest stomatal conductance and SPAD values in giant reed, and the highest stalk populations in elephant grass and

  19. Fluctuating water table affects gross ecosystem production and gross radiation use efficiency in a sedge-grass marsh

    Czech Academy of Sciences Publication Activity Database

    Dušek, Jiří; Čížková, Hana; Stellner, Stanislav; Czerný, Radek; Květ, Jan

    2012-01-01

    Roč. 692, č. 1 (2012), s. 57-66 ISSN 0018-8158 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŽP(CZ) SP/2D1/93/07; GA MŠk OC08021 Institutional research plan: CEZ:AV0Z60870520 Keywords : Wetland * fen * carbon * water level * Carex acuta L. * Eddy covariance Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.985, year: 2012

  20. Water

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-08-01

    Full Text Available Water scarcity is without a doubt on of the greatest threats to the human species and has all the potential to destabilise world peace. Falling water tables are a new phenomenon. Up until the development of steam and electric motors, deep groudwater...

  1. Efecto del agua aplicada en las relaciones hídricas y productividad de la vid 'Crimson Seedless' Effect of applied water on water relations and productivity of 'Crimson Seedless' table grapes

    Directory of Open Access Journals (Sweden)

    Raúl Ferreyra

    2006-07-01

    Full Text Available Este estudio fue dirigido para evaluar la relación agua-rendimiento en vid de mesa cv. Crimson y establecer valores críticos para las mediciones del estado hídrico de las plantas. Los estudios de campo se desarrollaron durante tres años, en el Valle de Aconcagua, Chile, a 32º47'S y 70º42'O, en un suelo de textura franco arcillosa. Se proporcionaron a las plantas diferentes cantidades de agua de riego entre 40 y 100% de la evapotranspiración del cultivo (Etc. El potencial hídrico xilemático medido a mediodía (psixmin y la conductancia estomática estuvieron estrechamente relacionados con el déficit de agua impuesto y el rendimiento obtenido. Los rendimientos de la vid disminuyeron respecto al agua aplicada en el rango de los tratamientos estudiados. Sesenta por ciento de restricción de la Etc redujo 22% del rendimiento. Cuando la planta mantuvo psixmin mayor que -0,75 MPa entre cuaja y pinta, la producción y los calibres fueron mayores.This study aimed to evaluate the relationship between water and production in 'Crimson Seedless' table grapes, and to establish threshold values for plants water status. Field experiments were carried out, during a three-year period, in the Aconcagua Valley, Chile, at 32º47'S and 70º42'W, in a clay-loamy textured soil. Different irrigation water amounts were applied, between 40 and 100% crop evapotranspiration (Etc. Stem water potential measured at midday (psixmin and stomatal conductance were closely related to water shortage and yield obtained. Table grape yields decreased in comparison with applied water within the range of studied treatments. Sixty per cent Etc restriction decreased yields in 22%. When plants maintained psixmin greater than -0.75 MPa, between berry set and veraison, yield and berry size were high.

  2. Pulse radiolysis of liquid water using picosecond electron pulses produced by a table-top terawatt laser system

    International Nuclear Information System (INIS)

    Saleh, Ned; Flippo, Kirk; Nemoto, Koshichi; Umstadter, Donald; Crowell, Robert A.; Jonah, Charles D.; Trifunac, Alexander D.

    2000-01-01

    A laser based electron generator is shown, for the first time, to produce sufficient charge to conduct time resolved investigations of radiation induced chemical events. Electron pulses generated by focussing terawatt laser pulses into a supersonic helium gas jet are used to ionize liquid water. The decay of the hydrated electrons produced by the ionizing electron pulses is monitored with 0.3 μs time resolution. Hydrated electron concentrations as high as 22 μM were generated. The results show that terawatt lasers offer both an alternative to linear accelerators and a means to achieve subpicosecond time resolution for pulse radiolysis studies. (c) 2000 American Institute of Physics

  3. VIDENTE: a graphical user interface and decision support system for stochastic modelling of water table fluctuations at a single location; includes documentation of the programs KALMAX, KALTFN, SSD and EMERALD and introductions to stochastic modellin

    NARCIS (Netherlands)

    Bierkens, M.F.P.; Bron, W.A.

    2000-01-01

    The VIDENTE program contains a decision support system (DSS) to choose between different models for stochastic modelling of water-table depths, and a graphical user interface to facilitate operating and running four implemented models: KALMAX, KALTFN,SSDS and EMERALD. In self-contained parts each of

  4. Monthly tables of measurements. October 2000

    International Nuclear Information System (INIS)

    2000-10-01

    This report of the O.P.R.I. (Office of Protection against Ionizing Radiations) exposes the principal results concerning the routine monitoring of environmental radioactivity in France: atmospheric dusts, rainwater, surface water, underground water, sewage water, drinking water, food chain (milk, vegetables, fishes), sea water around nuclear sites and other sites. The activities of various radioisotopes are presented in tables. (N.C.)

  5. Water

    International Nuclear Information System (INIS)

    Chovanec, A.; Grath, J.; Kralik, M.; Vogel, W.

    2002-01-01

    An up-date overview of the situation of the Austrian waters is given by analyzing the status of the water quality (groundwater, surface waters) and water protection measures. Maps containing information of nitrate and atrazine in groundwaters (analyses at monitoring stations), nitrate contents and biological water quality of running waters are included. Finally, pollutants (nitrate, orthophosphate, ammonium, nitrite, atrazine etc.) trends in annual mean values and median values for the whole country for the years 1992-1999 are presented in tables. Figs. 5. (nevyjel)

  6. Phloem as Capacitor: Radial Transfer of Water into Xylem of Tree Stems Occurs via Symplastic Transport in Ray Parenchyma[OPEN

    Science.gov (United States)

    Renard, Justine; Tjoelker, Mark G.; Salih, Anya

    2015-01-01

    The transfer of water from phloem into xylem is thought to mitigate increasing hydraulic tension in the vascular system of trees during the diel cycle of transpiration. Although a putative plant function, to date there is no direct evidence of such water transfer or the contributing pathways. Here, we trace the radial flow of water from the phloem into the xylem and investigate its diel variation. Introducing a fluorescent dye (0.1% [w/w] fluorescein) into the phloem water of the tree species Eucalyptus saligna allowed localization of the dye in phloem and xylem tissues using confocal laser scanning microscopy. Our results show that the majority of water transferred between the two tissues is facilitated via the symplast of horizontal ray parenchyma cells. The method also permitted assessment of the radial transfer of water during the diel cycle, where changes in water potential gradients between phloem and xylem determine the extent and direction of radial transfer. When injected during the morning, when xylem water potential rapidly declined, fluorescein was translocated, on average, farther into mature xylem (447 ± 188 µm) compared with nighttime, when xylem water potential was close to zero (155 ± 42 µm). These findings provide empirical evidence to support theoretical predictions of the role of phloem-xylem water transfer in the hydraulic functioning of plants. This method enables investigation of the role of phloem tissue as a dynamic capacitor for water storage and transfer and its contribution toward the maintenance of the functional integrity of xylem in trees. PMID:25588734

  7. The climate warming effect of a fen peat meadow with fluctuating water table is reduced by young alder trees

    Directory of Open Access Journals (Sweden)

    V. Huth

    2018-03-01

    Full Text Available Black alder (Alnus glutinosa (L. Gaertn. occurs naturally in temperate marshes and in minerotrophic peatlands and is also suitable for paludiculture - the cultivation of biomass on wet or rewetted peatland. We investigated the effect of a newly established black alder plantation on the greenhouse gas (GHG balance of a degraded fen in north-eastern Germany over a two-year period (August 2010–August 2012. We compared the alder plantation (Awet with an extensively used meadow (Mwet and a drier reference meadow (Mmoist. GHG fluxes were measured monthly to bi-monthly using the closed chamber method. Our results show that Awet was a slight net GHG (in CO2-eq sink of 3.4 ± 1.7 t ha-1 yr-1, Mwet was a moderate net GHG source of 9.6 ± 1.2 t ha 1 yr-1, and Mmoist was a strong net GHG source of 24.5 ± 1.6 t ha-1 yr-1. This was mainly driven by CO2 uptake at the two very moist (wet sites and by high CO2 release at the drier reference site. Awet was a larger CO2 sink than Mwet, probably due to additional CO2 uptake by the alder stand at Awet and carbon export in plant material harvested from Mwet. All sites were significant CH4 sources. Substantial CH4 emission peaks were observed at all sites following extraordinarily heavy precipitation during the summer of 2011, which accounted for up to 70 % of the accumulated two-year CH4 emissions. However, the Awet site generally emitted less CH4, possibly due to the effective oxygen transport mechanism in black alders. N2O emissions were negligible at all three sites. Our results indicate that the GHG balances of formerly drained fens benefit in the short term from planting of black alders, mostly due to reduced CH4 emissions. This study highlights the importance of acknowledging extreme precipitation events and groundwater fluctuations for the derivation of reliable GHG emission factors.

  8. Coupled eco-hydrology and biogeochemistry algorithms enable the simulation of water table depth effects on boreal peatland net CO2 exchange

    Science.gov (United States)

    Mezbahuddin, Mohammad; Grant, Robert F.; Flanagan, Lawrence B.

    2017-12-01

    Water table depth (WTD) effects on net ecosystem CO2 exchange of boreal peatlands are largely mediated by hydrological effects on peat biogeochemistry and the ecophysiology of peatland vegetation. The lack of representation of these effects in carbon models currently limits our predictive capacity for changes in boreal peatland carbon deposits under potential future drier and warmer climates. We examined whether a process-level coupling of a prognostic WTD with (1) oxygen transport, which controls energy yields from microbial and root oxidation-reduction reactions, and (2) vascular and nonvascular plant water relations could explain mechanisms that control variations in net CO2 exchange of a boreal fen under contrasting WTD conditions, i.e., shallow vs. deep WTD. Such coupling of eco-hydrology and biogeochemistry algorithms in a process-based ecosystem model, ecosys, was tested against net ecosystem CO2 exchange measurements in a western Canadian boreal fen peatland over a period of drier-weather-driven gradual WTD drawdown. A May-October WTD drawdown of ˜ 0.25 m from 2004 to 2009 hastened oxygen transport to microbial and root surfaces, enabling greater microbial and root energy yields and peat and litter decomposition, which raised modeled ecosystem respiration (Re) by 0.26 µmol CO2 m-2 s-1 per 0.1 m of WTD drawdown. It also augmented nutrient mineralization, and hence root nutrient availability and uptake, which resulted in improved leaf nutrient (nitrogen) status that facilitated carboxylation and raised modeled vascular gross primary productivity (GPP) and plant growth. The increase in modeled vascular GPP exceeded declines in modeled nonvascular (moss) GPP due to greater shading from increased vascular plant growth and moss drying from near-surface peat desiccation, thereby causing a net increase in modeled growing season GPP by 0.39 µmol CO2 m-2 s-1 per 0.1 m of WTD drawdown. Similar increases in GPP and Re caused no significant WTD effects on modeled

  9. Coupled eco-hydrology and biogeochemistry algorithms enable the simulation of water table depth effects on boreal peatland net CO2 exchange

    Directory of Open Access Journals (Sweden)

    M. Mezbahuddin

    2017-12-01

    Full Text Available Water table depth (WTD effects on net ecosystem CO2 exchange of boreal peatlands are largely mediated by hydrological effects on peat biogeochemistry and the ecophysiology of peatland vegetation. The lack of representation of these effects in carbon models currently limits our predictive capacity for changes in boreal peatland carbon deposits under potential future drier and warmer climates. We examined whether a process-level coupling of a prognostic WTD with (1 oxygen transport, which controls energy yields from microbial and root oxidation–reduction reactions, and (2 vascular and nonvascular plant water relations could explain mechanisms that control variations in net CO2 exchange of a boreal fen under contrasting WTD conditions, i.e., shallow vs. deep WTD. Such coupling of eco-hydrology and biogeochemistry algorithms in a process-based ecosystem model, ecosys, was tested against net ecosystem CO2 exchange measurements in a western Canadian boreal fen peatland over a period of drier-weather-driven gradual WTD drawdown. A May–October WTD drawdown of  ∼  0.25 m from 2004 to 2009 hastened oxygen transport to microbial and root surfaces, enabling greater microbial and root energy yields and peat and litter decomposition, which raised modeled ecosystem respiration (Re by 0.26 µmol CO2 m−2 s−1 per 0.1 m of WTD drawdown. It also augmented nutrient mineralization, and hence root nutrient availability and uptake, which resulted in improved leaf nutrient (nitrogen status that facilitated carboxylation and raised modeled vascular gross primary productivity (GPP and plant growth. The increase in modeled vascular GPP exceeded declines in modeled nonvascular (moss GPP due to greater shading from increased vascular plant growth and moss drying from near-surface peat desiccation, thereby causing a net increase in modeled growing season GPP by 0.39 µmol CO2 m−2 s−1 per 0.1 m of WTD drawdown. Similar increases in

  10. Experimental study of the hydrodynamic instabilities occurring in boiling-water reactors; Etude experimentale des instabilites hydrodynamiques survenant dans les reacteurs nucleaires a ebullition

    Energy Technology Data Exchange (ETDEWEB)

    Fabreca, S. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-10-01

    The subjects is an experimental out-of pile loop study of the hydrodynamic oscillations occurring in boiling-water reactors. The study was carried out at atmospheric pressure and at pressure of about 8 atmospheres, in channels heated electrically by a constant and uniform specified current. In the test at 8 atmospheres the channel was a round tube of approximately 6 mm interior diameter. At 1 atmosphere a ring-section channel was used, 10 * 20 mm in diameter, with an inner heating tube and an outer tube of pyrex. It was possible to operate with natural convection and also with forced convection with test-channel by-pass. The study consists of 3 parts: 1. Preliminary determination of the laws governing pressure-drop during boiling. 2. Determination of the fronts at which oscillation appears, within a wide range of the parameters involved. 3. A descriptive study of the oscillations and measurement of the periods. The report gives the oscillation fronts with natural and forced convection for various values of the singular pressure drop at the channel inlet and for various riser lengths. The results are presented in non-dimensional form, which is available, in first approximation, for all geometric scales and for all fluids. Besides the following points were observed: - the wall (nature and thickness) can be an important factor ; - oscillation can occur in a horizontal channel. (author) [French] II a ete effectue une etude experimentale, en boucle hors-pile, des oscillations hydrodynamiques survenant dans les reacteurs a ebullition. L'etude a ete effectuee a la pression atmospherique et a une pression voisine de 8 atmospheres dans des canaux chauffes electriquement a puissance imposee constante et uniforme. Dans les essais a 8 atmospheres le canal etait un tube circulaire de diametre interieur 6 mm environ. A 1 atmosphere le canal etait de section annulaire 10 * 20 mm avec un tube interieur chauffant et un tube exterieur en pyrex. Le fonctionnement etait possible

  11. Experimental study of the hydrodynamic instabilities occurring in boiling-water reactors; Etude experimentale des instabilites hydrodynamiques survenant dans les reacteurs nucleaires a ebullition

    Energy Technology Data Exchange (ETDEWEB)

    Fabreca, S [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-10-01

    The subjects is an experimental out-of pile loop study of the hydrodynamic oscillations occurring in boiling-water reactors. The study was carried out at atmospheric pressure and at pressure of about 8 atmospheres, in channels heated electrically by a constant and uniform specified current. In the test at 8 atmospheres the channel was a round tube of approximately 6 mm interior diameter. At 1 atmosphere a ring-section channel was used, 10 * 20 mm in diameter, with an inner heating tube and an outer tube of pyrex. It was possible to operate with natural convection and also with forced convection with test-channel by-pass. The study consists of 3 parts: 1. Preliminary determination of the laws governing pressure-drop during boiling. 2. Determination of the fronts at which oscillation appears, within a wide range of the parameters involved. 3. A descriptive study of the oscillations and measurement of the periods. The report gives the oscillation fronts with natural and forced convection for various values of the singular pressure drop at the channel inlet and for various riser lengths. The results are presented in non-dimensional form, which is available, in first approximation, for all geometric scales and for all fluids. Besides the following points were observed: - the wall (nature and thickness) can be an important factor ; - oscillation can occur in a horizontal channel. (author) [French] II a ete effectue une etude experimentale, en boucle hors-pile, des oscillations hydrodynamiques survenant dans les reacteurs a ebullition. L'etude a ete effectuee a la pression atmospherique et a une pression voisine de 8 atmospheres dans des canaux chauffes electriquement a puissance imposee constante et uniforme. Dans les essais a 8 atmospheres le canal etait un tube circulaire de diametre interieur 6 mm environ. A 1 atmosphere le canal etait de section annulaire 10 * 20 mm avec un tube interieur chauffant et un tube exterieur en pyrex. Le fonctionnement etait possible en

  12. Stability analysis of roadway embankments supported by stone columns with the presence of water table under short-term and long-term conditions

    Directory of Open Access Journals (Sweden)

    Kadhim Shaymaa Tareq

    2018-01-01

    Full Text Available Use of stone column technique to improve soft foundation soils under roadway embankments has proven to increase the bearing capacity and reduce the potential settlement. The potential contribution of stone columns to the stability of roadway embankments against general (i.e. deep-seated failure needs to be thoroughly investigated. Therefore, a two-dimensional finite difference model implemented by FLAC/SLOPE 7.0 software, was employed in this study to assess the stability of a roadway embankment fill built on a soft soil deposit improved by stone column technique. The stability factor of safety was obtained numerically under both short-term and long-term conditions with the presence of water table. Two methods were adopted to convert the three-dimensional model into plane strain condition: column wall and equivalent improved ground methods. The effect of various parameters was studied to evaluate their influence on the factor of safety against embankment instability. For instance, the column diameter, columns’ spacing, soft soil properties for short-term and long-term conditions, and the height and friction angle of the embankment fill. The results of this study are developed in several design charts.

  13. Water-table and discharge changes associated with the 2016-2017 seismic sequence in central Italy: hydrogeological data and a conceptual model for fractured carbonate aquifers

    Science.gov (United States)

    Petitta, Marco; Mastrorillo, Lucia; Preziosi, Elisabetta; Banzato, Francesca; Barberio, Marino Domenico; Billi, Andrea; Cambi, Costanza; De Luca, Gaetano; Di Carlo, Giuseppe; Di Curzio, Diego; Di Salvo, Cristina; Nanni, Torquato; Palpacelli, Stefano; Rusi, Sergio; Saroli, Michele; Tallini, Marco; Tazioli, Alberto; Valigi, Daniela; Vivalda, Paola; Doglioni, Carlo

    2018-01-01

    A seismic sequence in central Italy from August 2016 to January 2017 affected groundwater dynamics in fractured carbonate aquifers. Changes in spring discharge, water-table position, and streamflow were recorded for several months following nine Mw 5.0-6.5 seismic events. Data from 22 measurement sites, located within 100 km of the epicentral zones, were analyzed. The intensity of the induced changes were correlated with seismic magnitude and distance to epicenters. The additional post-seismic discharge from rivers and springs was found to be higher than 9 m3/s, totaling more than 0.1 km3 of groundwater release over 6 months. This huge and unexpected contribution increased streamflow in narrow mountainous valleys to previously unmeasured peak values. Analogously to the L'Aquila 2009 post-earthquake phenomenon, these hydrogeological changes might reflect an increase of bulk hydraulic conductivity at the aquifer scale, which would increase hydraulic heads in the discharge zones and lower them in some recharge areas. The observed changes may also be partly due to other mechanisms, such as shaking and/or squeezing effects related to intense subsidence in the core of the affected area, where effects had maximum extent, or breaching of hydraulic barriers.

  14. Crop water parameters of irrigated wine and table grapes to support water productivity analysis in the Sao Francisco river basin, Brazil

    NARCIS (Netherlands)

    Castro Teixeira, de A.H.; Bastiaanssen, W.G.M.; Bassoi, L.H.

    2007-01-01

    Energy and water balance parameters were measured in two commercial vineyards in the semiarid region of the São Francisco river basin, Brazil. Actual evapotranspiration (ET) was acquired with the Bowen ratio surface energy balance method. The ratio of the latent heat flux to the available energy, or

  15. Dynamics of Soil Water Evaporation during Soil Drying in the Presence of a Shallow Water Table: Laboratory Experiment and Numerical Analysis

    Science.gov (United States)

    Han, J.; Lin, J.; Liu, P.; Li, W.

    2017-12-01

    Evaporation from a porous medium plays a key role in hydrological, agricultural, environmental, and engineering applications. Laboratory and numerical experiments were conducted to investigate the evolution of soil water evaporation during a continuous drying event. Simulated soil water contents and temperatures by the calibrated model well reproduced measured values at different depths. Results show that the evaporative drying process could be divided into three stages, beginning with a relatively high evaporation rate during stage 1, followed by a lower rate during transient stage and stage 2, and finally maintaining a very low and constant rate during stage 3. The condensation zone was located immediately below the evaporation zone in the profile. Both peaks of evaporation and condensation rate increased rapidly during stage 1 and transition stage, decreased during stage 2, and maintained constant during stage 3. The width of evaporation zone kept a continuous increase during stages 1 and 2 and maintained a nearly constant value of 0.68 cm during stage 3. When the evaporation zone totally moved into the subsurface, a dry surface layer (DSL) formed above the evaporation zone at the end of stage 2. The width of DSL also presented a continuous increase during stage 2 and kept a constant value of 0.71 cm during stage 3. Although the magnitude of condensation zone was much smaller than that for the evaporation zone, the importance of the contribution of condensation zone to soil water dynamics should not be underestimated. Results from our experiment and numerical simulation show that this condensation process resulted in an unexpected and apparent water content increase in the middle of vadose zone profile.

  16. Co-Occurring Disorders

    Science.gov (United States)

    ... the mental health field. Alcohol and Drug Abuse, Addiction and Co-occurring Disorders: Co-occurring Disorders and ... 500 Montgomery Street, Suite 820 Alexandria, VA 22314 Phone (703) 684.7722 Toll Free (800) 969.6642 ...

  17. Water quality in the vicinity of Mosquito Creek Lake, Trumbull County, Ohio, in relation of the chemistry of locally occurring oil, natural gas, and brine

    International Nuclear Information System (INIS)

    Barton, G.J.; Burruss, R.C.; Ryder, R.T.

    1998-01-01

    The purpose of this report is to describe current water quality and the chemistry of oil, natural gas, and brine in the Mosquito Creek Lake area. Additionally, these data are used to characterize water quality in the Mosquito Creek Lake area in relation to past oil and natural gas well drilling and production. To meet the overall objective, several goals for this investigation were established. These include (1) collect water-quality and subsurface-gas data from shallow sediments and rock that can be used for future evaluation of possible effects of oil and natural gas well drilling and production on water supplies, (2) characterize current surface-water and ground-water quality as it relates to the natural occurrence and (or) release of oil, gas, and brine (3) sample and chemically characterize the oil in the shallow Mecca Oil Pool, gas from the Berea and Cussewago Sandstone aquifers, and the oil, gas, and brine from the Clinton sandstone, and (4) identify areas where aquifers are vulnerable to contamination from surface spills at oil and natural gas drilling and production sites

  18. APEX (Aqueous Photochemistry of Environmentally occurring Xenobiotics): a free software tool to predict the kinetics of photochemical processes in surface waters.

    Science.gov (United States)

    Bodrato, Marco; Vione, Davide

    2014-04-01

    The APEX software predicts the photochemical transformation kinetics of xenobiotics in surface waters as a function of: photoreactivity parameters (direct photolysis quantum yield and second-order reaction rate constants with transient species, namely ˙OH, CO₃(-)˙, (1)O₂ and the triplet states of chromophoric dissolved organic matter, (3)CDOM*), water chemistry (nitrate, nitrite, bicarbonate, carbonate, bromide and dissolved organic carbon, DOC), and water depth (more specifically, the optical path length of sunlight in water). It applies to well-mixed surface water layers, including the epilimnion of stratified lakes, and the output data are average values over the considered water column. Based on intermediate formation yields from the parent compound via the different photochemical pathways, the software can also predict intermediate formation kinetics and overall yield. APEX is based on a photochemical model that has been validated against available field data of pollutant phototransformation, with good agreement between model predictions and field results. The APEX software makes allowance for different levels of knowledge of a photochemical system. For instance, the absorption spectrum of surface water can be used if known, or otherwise it can be modelled from the values of DOC. Also the direct photolysis quantum yield can be entered as a detailed wavelength trend, as a single value (constant or average), or it can be defined as a variable if unknown. APEX is based on the free software Octave. Additional applications are provided within APEX to assess the σ-level uncertainty of the results and the seasonal trend of photochemical processes.

  19. Geochemical characterization of fluoride in water, table salt, active sediment, rock and soil samples, and its possible relationship with the prevalence of enamel fluorosis in children in four municipalities of the department of Huila (Colombia).

    Science.gov (United States)

    Martignon, Stefania; Opazo-Gutiérrez, Mario Omar; Velásquez-Riaño, Möritz; Orjuela-Osorio, Iván Rodrigo; Avila, Viviana; Martinez-Mier, Esperanza Angeles; González-Carrera, María Clara; Ruiz-Carrizosa, Jaime Alberto; Silva-Hermida, Blanca Cecilia

    2017-06-01

    Fluoride is an element that affects teeth and bone formation in animals and humans. Though the use of systemic fluoride is an evidence-based caries preventive measure, excessive ingestion can impair tooth development, mainly the mineralization of tooth enamel, leading to a condition known as enamel fluorosis. In this study, we investigated the geochemical characterization of fluoride in water, table salt, active sediment, rock and soil samples in four endemic enamel fluorosis sentinel municipalities of the department of Huila, Colombia (Pitalito, Altamira, El Agrado and Rivera), and its possible relationship with the prevalence of enamel fluorosis in children. The concentration of fluoride in drinking water, table salt, active sediment, rock, and soil was evaluated by means of an ion selective electrode and the geochemical analyses were performed using X-ray fluorescence. Geochemical analysis revealed fluoride concentrations under 15 mg/kg in active sediment, rock and soil samples, not indicative of a significant delivery to the watersheds studied. The concentration of fluoride in table salt was found to be under the inferior limit (less than 180 μg/g) established by the Colombian regulations. Likewise, exposure doses for fluoride water intake did not exceed the recommended total dose for all ages from 6 months. Although the evidence does not point out at rocks, soils, fluoride-bearing minerals, fluoridated salt and water, the hypothesis of these elements as responsible of the current prevalence of enamel fluorosis cannot be discarded since, aqueducts might have undergone significant changes overtime.

  20. NNDSS - Table III. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table III. Tuberculosis - 2018.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  1. Pension Insurance Data Tables

    Data.gov (United States)

    Pension Benefit Guaranty Corporation — Find out about retirement trends in PBGC's data tables. The tables include statistics on the people and pensions that PBGC protects, including how many Americans are...

  2. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2016.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  3. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2014.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  4. NNDSS - Table II. Vibriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Vibriosis - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year), and selected...

  5. NNDSS - Table III. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table III. Tuberculosis - 2017.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  6. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2015.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  7. NNDSS - Table II. Vibriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Vibriosis - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year), and selected...

  8. Tabled Execution in Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Willcock, J J; Lumsdaine, A; Quinlan, D J

    2008-08-19

    Tabled execution is a generalization of memorization developed by the logic programming community. It not only saves results from tabled predicates, but also stores the set of currently active calls to them; tabled execution can thus provide meaningful semantics for programs that seemingly contain infinite recursions with the same arguments. In logic programming, tabled execution is used for many purposes, both for improving the efficiency of programs, and making tasks simpler and more direct to express than with normal logic programs. However, tabled execution is only infrequently applied in mainstream functional languages such as Scheme. We demonstrate an elegant implementation of tabled execution in Scheme, using a mix of continuation-passing style and mutable data. We also show the use of tabled execution in Scheme for a problem in formal language and automata theory, demonstrating that tabled execution can be a valuable tool for Scheme users.

  9. Filling the gap: using non-invasive geophysical methods to monitor the processes leading to enhanced carbon turnover induced by periodic water table fluctuations

    Science.gov (United States)

    Mellage, A.; Pronk, G.; Atekwana, E. A.; Furman, A.; Rezanezhad, F.; Van Cappellen, P.

    2017-12-01

    Subsurface transition environments such as the capillary fringe are characterized by steep gradients in redox conditions. Spatial and temporal variations in electron acceptor and donor availability - driven by hydrological changes - may enhance carbon turnover, in some cases resulting in pulses of CO2-respiration. Filling the mechanistic knowledge gap between the hydrological driver and its biogeochemical effects hinges on our ability to monitor microbial activity and key geochemical markers at a high spatial and temporal resolution. However, direct access to subsurface biogeochemical processes is logistically difficult, invasive and usually expensive. In-line, non-invasive geophysical techniques - Spectral Induced Polarization (SIP) and Electrodic Potential (EP), specifically - offer a comparatively inexpensive alternative and can provide data with high spatial and temporal resolution. The challenge lies in linking electrical responses to specific changes in biogeochemical processes. We conducted SIP and EP measurements on a soil column experiment where an artificial soil mixture was subjected to monthly drainage and imbibition cycles. SIP responses showed a clear dependence on redox zonation and microbial abundance. Temporally variable responses exhibited no direct moisture dependence suggesting that the measured responses recorded changes in microbial activity and coincided with the depth interval over which enhanced carbon turnover was observed. EP measurements detected the onset of sulfate mineralization and mapped its depth zonation. SIP and EP signals thus detected enhanced microbial activity within the water table fluctuation zone as well as the timing of the development of specific reactive processes. These findings can be used to relate measured electrical signals to specific reaction pathways and help inform reactive transport models, increasing their predictive capabilities.

  10. Experimental study and calculation of boiling heat transfer on steel plates during runout table operation

    International Nuclear Information System (INIS)

    Liu, Z.D.; Fraser, D.; Samarasekera, I.V.

    2002-01-01

    Within a hot strip steel mill, red hot steel is hot rolled into a long continuous slab that is led onto what is called the runout table. Temperatures of the steel at the beginning of this table are around 900 o C. Above and below the runout table are banks of water jets, sprays or water curtains that rapidly cool the steel slab. The heat transfer process itself may be considered one of the most complicated in the industrial world. The cooling process that occurs on the runout table is crucial and governs the final mechanical properties and flatness of a steel strip. However, very limited data of industrial conditions has been available and that which is available is poorly understood. To study heat transfer during runout table cooling, an industrial scale pilot runout table facility was constructed at the University of British Columbia (UBC). This paper describes the experimental details, data acquisition and data handling techniques for steel plates during water jet impingement cooling by one circular water jet from industrial headers. The effect of cooling water temperature and initial steel plate temperature as well as varying water jet diameters on heat transfer was systematically investigated. A two-dimensional finite element scheme based inverse heat conduction model was developed to calculate surface heat transfer coefficients along the impinging surface. Heat flux curves at the stagnation area were obtained for selected tests. A quantitative relationship between adjustable processing parameters and heat transfer coefficients along the impinging surface during runout table operation is discussed. The results of the study were used to upgrade an extensive process model developed at UBC. The model ties in the cooling rate and hence two dimensional temperature gradients to the resulting microstructure and final mechanical properties of the steel. This process model is widely used by major steel industries in Canada and the United States. (author)

  11. AcuTable

    DEFF Research Database (Denmark)

    Dibbern, Simon; Rasmussen, Kasper Vestergaard; Ortiz-Arroyo, Daniel

    2017-01-01

    In this paper we describe AcuTable, a new tangible user interface. AcuTable is a shapeable surface that employs capacitive touch sensors. The goal of AcuTable was to enable the exploration of the capabilities of such haptic interface and its applications. We describe its design and implementation...

  12. Table Tennis Club

    CERN Multimedia

    Table Tennis Club

    2013-01-01

    Apparently table tennis plays an important role in physics, not so much because physicists are interested in the theory of table tennis ball scattering, but probably because it provides useful breaks from their deep intellectual occupation. It seems that many of the greatest physicists took table tennis very seriously. For instance, Heisenberg could not even bear to lose a game of table tennis, Otto Frisch played a lot of table tennis, and had a table set up in his library, and Niels Bohr apparently beat everybody at table tennis. Therefore, as the CERN Table Tennis Club advertises on a poster for the next CERN Table Tennis Tournament: “if you want to be a great physicist, perhaps you should play table tennis”. Outdoor table at restaurant n° 1 For this reason, and also as part of the campaign launched by the CERN medical service “Move! & Eat better”, to encourage everyone at CERN to take regular exercise, the CERN Table Tennis Club, with the supp...

  13. Periodic Table of Students.

    Science.gov (United States)

    Johnson, Mike

    1998-01-01

    Presents an exercise in which an eighth-grade science teacher decorated the classroom with a periodic table of students. Student photographs were arranged according to similarities into vertical columns. Students were each assigned an atomic number according to their placement in the table. The table is then used to teach students about…

  14. Comparison of leaf gas exchange and stable isotope signature of water-soluble compounds along canopy gradients of co-occurring Douglas-fir and European beech.

    Science.gov (United States)

    Bögelein, Rebekka; Hassdenteufel, Martin; Thomas, Frank M; Werner, Willy

    2012-07-01

    Combined δ(13) C and δ(18) O analyses of water-soluble leaf and twig phloem material were used to determine intrinsic water-use efficiency (iWUE) and variability of stomatal conductance at different crown positions in adult European beech (Fagus sylvatica) and Douglas-fir (Pseudotsuga menziesii) trees. Simultaneous gas exchange measurements allowed evaluation of the differences in calculating iWUE from leaf or phloem water-soluble compounds, and comparison with a semi-quantitative dual isotope model to infer variability of net photosynthesis (A(n) ) between the investigated crown positions. Estimates of iWUE from δ(13) C of leaf water-soluble organic matter (WSOM) outperformed the estimates from phloem compounds. In the beech crown, δ(13) C of leaf WSOM coincided clearly with gas exchange measurements. The relationship was not as reliable in the Douglas-fir. The differences in δ(18) O between leaf and phloem material were found to correlate with stomatal conductance. The semi-quantitative model approach was applicable for comparisons of daily average A(n) between different crown positions and trees. Intracanopy gradients were more pronounced in the beech than in the Douglas-fir, which reached higher values of iWUE at the respective positions, particularly under dry air conditions. © 2012 Blackwell Publishing Ltd.

  15. Carbon dioxide flux and net primary production of a boreal treed bog: Responses to warming and water-table-lowering simulations of climate change

    Science.gov (United States)

    Munir, T. M.; Perkins, M.; Kaing, E.; Strack, M.

    2015-02-01

    Midlatitude treed bogs represent significant carbon (C) stocks and are highly sensitive to global climate change. In a dry continental treed bog, we compared three sites: control, recent (1-3 years; experimental) and older drained (10-13 years), with water levels at 38, 74 and 120 cm below the surface, respectively. At each site we measured carbon dioxide (CO2) fluxes and estimated tree root respiration (Rr; across hummock-hollow microtopography of the forest floor) and net primary production (NPP) of trees during the growing seasons (May to October) of 2011-2013. The CO2-C balance was calculated by adding the net CO2 exchange of the forest floor (NEff-Rr) to the NPP of the trees. From cooler and wetter 2011 to the driest and the warmest 2013, the control site was a CO2-C sink of 92, 70 and 76 g m-2, the experimental site was a CO2-C source of 14, 57 and 135 g m-2, and the drained site was a progressively smaller source of 26, 23 and 13 g CO2-C m-2. The short-term drainage at the experimental site resulted in small changes in vegetation coverage and large net CO2 emissions at the microforms. In contrast, the longer-term drainage and deeper water level at the drained site resulted in the replacement of mosses with vascular plants (shrubs) on the hummocks and lichen in the hollows leading to the highest CO2 uptake at the drained hummocks and significant losses in the hollows. The tree NPP (including above- and below-ground growth and litter fall) in 2011 and 2012 was significantly higher at the drained site (92 and 83 g C m-2) than at the experimental (58 and 55 g C m-2) and control (52 and 46 g C m-2) sites. We also quantified the impact of climatic warming at all water table treatments by equipping additional plots with open-top chambers (OTCs) that caused a passive warming on average of ~ 1 °C and differential air warming of ~ 6 °C at midday full sun over the study years. Warming significantly enhanced shrub growth and the CO2 sink function of the drained

  16. Tracing water movement in Mumbai harbor bay using naturally occurring "2"2"4Ra and "2"2"3Ra as tracer

    International Nuclear Information System (INIS)

    Yadav, V.B.; Sartandel, S.J.; Jha, S.K.; Tripathi, R.M.

    2017-01-01

    Measurement of short lived radium isotopes "2"2"4Ra and "2"2"3Ra in seawater samples collected from Mumbai Harbor Bay was carried out using MnO_2 based in-situ pre-concentration technique coupled with coincidence counting. Longitudinal variation of "2"2"4Ra and "2"2"3Ra was found in the range 17.74 - 98.66 dpm/100L and 0.56 - 2.26 dpm/100L respectively. Higher value of radium isotopes was found near shore sampling points where reused seawater and surface water from land intrudes in creek. A decreasing pattern was observed in the creek as we move to offshore locations. Lower activity ratio in offshore locations indicates the flow of water towards open sea. (author)

  17. Mortality table construction

    Science.gov (United States)

    Sutawanir

    2015-12-01

    Mortality tables play important role in actuarial studies such as life annuities, premium determination, premium reserve, valuation pension plan, pension funding. Some known mortality tables are CSO mortality table, Indonesian Mortality Table, Bowers mortality table, Japan Mortality table. For actuary applications some tables are constructed with different environment such as single decrement, double decrement, and multiple decrement. There exist two approaches in mortality table construction : mathematics approach and statistical approach. Distribution model and estimation theory are the statistical concepts that are used in mortality table construction. This article aims to discuss the statistical approach in mortality table construction. The distributional assumptions are uniform death distribution (UDD) and constant force (exponential). Moment estimation and maximum likelihood are used to estimate the mortality parameter. Moment estimation methods are easier to manipulate compared to maximum likelihood estimation (mle). However, the complete mortality data are not used in moment estimation method. Maximum likelihood exploited all available information in mortality estimation. Some mle equations are complicated and solved using numerical methods. The article focus on single decrement estimation using moment and maximum likelihood estimation. Some extension to double decrement will introduced. Simple dataset will be used to illustrated the mortality estimation, and mortality table.

  18. CERN Table Tennis Club

    CERN Multimedia

    CERN Table Tennis Club

    2014-01-01

    CERN Table Tennis Club Announcing CERN 60th Anniversary Table Tennis Tournament to take place at CERN, from July 1 to July 15, 2014   The CERN Table Tennis Club, reborn in 2008, is encouraging people at CERN to take more regular exercise. This is why the Club, thanks to the strong support of the CERN Staff Association, installed last season a first outdoor table on the terrace of restaurant # 1, and will install another one this season on the terrace of Restaurant # 2. Table tennis provides both physical exercise and friendly social interactions. The CERN Table Tennis club is happy to use the unique opportunity of the 60th CERN anniversary to promote table tennis at CERN, as it is a game that everybody can easily play, regardless of level. Table tennis is particularly well suited for CERN, as many great physicists play table tennis, as you might already know: “Heisenberg could not even bear to lose a game of table tennis”; “Otto Frisch played a lot of table tennis;...

  19. Ground water conditions and the relation to uranium deposits in the Gas Hills area, Fremont and Natrona Counties, Wyoming

    International Nuclear Information System (INIS)

    Marks, L.Y.

    1978-03-01

    As ground water apparently leaches, transports, and deposits uranium in the Gas Hills area, central Wyoming, it is important to understand its distribution, movement, and relation to geology and ore bodies. Water table maps were prepared of the Wind River Basin; the most detailed work was in the Gas Hills area. The water table in the Gas Hills area slopes downward to the northwest, ranges in depth from near the ground surface to more than 200 feet, and has seasonal fluctuation of about five feet. Perched water tables and artesian conditions occur locally. The oxidized-unoxidized rock contact is probably roughly parallel to the water table, and averages about 25 feet above it; although locally the two surfaces are considerably farther apart and the oxidized-unoxidized contact may be below the water table. In many places the gradient of the water table changes near the contact between rocks of different permeability. It is conformable with the structure at some anticlines and its gradient changes abruptly near some faults. Most above-normal concentrations of uranium occur at local water table depressions or at water table terraces where the gradient of the water table flattens. At these places, the uraniferous ground water is slowed and is in contact with the reducing agents in the rocks for a relatively long time. This may allow reduction of soluble transported uranium (U +6 ) to insoluble U +4 ) so that uranium is precipitated

  20. TABLE TENNIS CLUB

    CERN Document Server

    TABLE TENNIS CLUB

    2010-01-01

    2010 CERN Table Tennis Tournament The CERN Table Tennis Club organizes its traditional CERN Table Tennis Tournament, at the Meyrin club, 2 rue de livron, in Meyrin, Saturday August 21st, in the afternoon. The tournament is open to all CERN staff, users, visitors and families, including of course summer students. See below for details. In order to register, simply send an E-mail to Jean-Pierre Revol (jean-pierre.revol@cern.ch). You can also download the registration form from the Club Web page (http://www.cern.ch/tabletennis), and send it via internal mail. Photo taken on August 22, 2009 showing some of the participants in the 2nd CERN Table Tennis tournament. INFORMATION ON CERN TABLE TENNIS CLUB CERN used to have a tradition of table tennis activities at CERN. For some reason, at the beginning of the 1980’s, the CERN Table Tennis club merged with the Meyrin Table Tennis club, a member of the Association Genevoise de Tennis de Table (AGTT). Therefore, if you want to practice table tennis, you...

  1. Standard Reference Tables -

    Data.gov (United States)

    Department of Transportation — The Standard Reference Tables (SRT) provide consistent reference data for the various applications that support Flight Standards Service (AFS) business processes and...

  2. Evaluation of a computer model to simulate water table response to subirrigation Avaliação de um modelo computacional para simular a resposta do lençol freático à subirrigação

    Directory of Open Access Journals (Sweden)

    Jadir Aparecido Rosa

    2002-12-01

    Full Text Available The objective of this work was to evaluate the water flow computer model, WATABLE, using experimental field observations on water table management plots from a site located near Hastings, FL, USA. The experimental field had scale drainage systems with provisions for subirrigation with buried microirrigation and conventional seepage irrigation systems. Potato (Solanum tuberosum L. growing seasons from years 1996 and 1997 were used to simulate the hydrology of the area. Water table levels, precipitation, irrigation and runoff volumes were continuously monitored. The model simulated the water movement from a buried microirrigation line source and the response of the water table to irrigation, precipitation, evapotranspiration, and deep percolation. The model was calibrated and verified by comparing simulated results with experimental field observations. The model performed very well in simulating seasonal runoff, irrigation volumes, and water table levels during crop growth. The two-dimensional model can be used to investigate different irrigation strategies involving water table management control. Applications of the model include optimization of the water table depth for each growth stage, and duration, frequency, and rate of irrigation.O objetivo deste trabalho foi avaliar o modelo computacional WATABLE usando-se dados de campo obtidos em uma área experimental em manejo de lençol freático, localizada em Hastings, FL, EUA. Na área experimental, estavam instalados um sistema de drenagem e sistemas de irrigação por subsuperfície com irrigação localizada e por canais. Ciclos de cultivo de batata (Solanum tuberosum L., nos anos de 1996 e 1997, foram usados para a simulação da hidrologia da área. Profundidades do lençol freático, chuvas, irrigação e escorrimento superficial foram monitorados constantemente. O modelo simulou o movimento da água a partir de uma linha de irrigação localizada enterrada, e a resposta do nível do len

  3. High temporal resolution modeling of the impact of rain, tides, and sea level rise on water table flooding in the Arch Creek basin, Miami-Dade County Florida USA.

    Science.gov (United States)

    Sukop, Michael C; Rogers, Martina; Guannel, Greg; Infanti, Johnna M; Hagemann, Katherine

    2018-03-01

    Modeling of groundwater levels in a portion of the low-lying coastal Arch Creek basin in northern Miami-Dade County in Southeast Florida USA, which is subject to repetitive flooding, reveals that rain-induced short-term water table rises can be viewed as a primary driver of flooding events under current conditions. Areas below 0.9m North American Vertical Datum (NAVD) elevation are particularly vulnerable and areas below 1.5m NAVD are vulnerable to exceptionally large rainfall events. Long-term water table rise is evident in the groundwater data, and the rate appears to be consistent with local rates of sea level rise. Linear extrapolation of long-term observed groundwater levels to 2060 suggest roughly a doubling of the number of days when groundwater levels exceed 0.9m NAVD and a threefold increase in the number of days when levels exceed 1.5m NAVD. Projected sea level rise of 0.61m by 2060 together with increased rainfall lead to a model prediction of frequent groundwater-related flooding in areas1.5m NAVD and widespread flooding of the area in the past. Tidal fluctuations in the water table are predicted to be more pronounced within 600m of a tidally influenced water control structure that is hydrodynamically connected to Biscayne Bay. The inland influence of tidal fluctuations appears to increase with increased sea level, but the principal driver of high groundwater levels under the 2060 scenario conditions remains groundwater recharge due to rainfall events. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. The Living Periodic Table

    Science.gov (United States)

    Nahlik, Mary Schrodt

    2005-01-01

    To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…

  5. Qualification of the calculational methods of the fluence in the pressurised water reactors. Improvement of the cross sections treatment by the probability table method

    International Nuclear Information System (INIS)

    Zheng, S.H.

    1994-01-01

    It is indispensable to know the fluence on the nuclear reactor pressure vessel. The cross sections and their treatment have an important rule to this problem. In this study, two ''benchmarks'' have been interpreted by the Monte Carlo transport program TRIPOLI to qualify the calculational method and the cross sections used in the calculations. For the treatment of the cross sections, the multigroup method is usually used but it exists some problems such as the difficulty to choose the weighting function and the necessity of a great number of energy to represent well the cross section's fluctuation. In this thesis, we propose a new method called ''Probability Table Method'' to treat the neutron cross sections. For the qualification, a program of the simulation of neutron transport by the Monte Carlo method in one dimension has been written; the comparison of multigroup's results and probability table's results shows the advantages of this new method. The probability table has also been introduced in the TRIPOLI program; the calculational results of the iron deep penetration benchmark has been improved by comparing with the experimental results. So it is interest to use this new method in the shielding and neutronic calculation. (author). 42 refs., 109 figs., 36 tabs

  6. Naturally Occurring Radioactive Materials (NORM)

    International Nuclear Information System (INIS)

    Gray, P.

    1997-01-01

    This paper discusses the broad problems presented by Naturally Occuring Radioactive Materials (NORM). Technologically Enhanced naturally occuring radioactive material includes any radionuclides whose physical, chemical, radiological properties or radionuclide concentration have been altered from their natural state. With regard to NORM in particular, radioactive contamination is radioactive material in an undesired location. This is a concern in a range of industries: petroleum; uranium mining; phosphorus and phosphates; fertilizers; fossil fuels; forestry products; water treatment; metal mining and processing; geothermal energy. The author discusses in more detail the problem in the petroleum industry, including the isotopes of concern, the hazards they present, the contamination which they cause, ways to dispose of contaminated materials, and regulatory issues. He points out there are three key programs to reduce legal exposure and problems due to these contaminants: waste minimization; NORM assesment (surveys); NORM compliance (training)

  7. Naturally Occurring Radioactive Materials (NORM)

    Energy Technology Data Exchange (ETDEWEB)

    Gray, P. [ed.

    1997-02-01

    This paper discusses the broad problems presented by Naturally Occuring Radioactive Materials (NORM). Technologically Enhanced naturally occuring radioactive material includes any radionuclides whose physical, chemical, radiological properties or radionuclide concentration have been altered from their natural state. With regard to NORM in particular, radioactive contamination is radioactive material in an undesired location. This is a concern in a range of industries: petroleum; uranium mining; phosphorus and phosphates; fertilizers; fossil fuels; forestry products; water treatment; metal mining and processing; geothermal energy. The author discusses in more detail the problem in the petroleum industry, including the isotopes of concern, the hazards they present, the contamination which they cause, ways to dispose of contaminated materials, and regulatory issues. He points out there are three key programs to reduce legal exposure and problems due to these contaminants: waste minimization; NORM assesment (surveys); NORM compliance (training).

  8. Elementary Statistics Tables

    CERN Document Server

    Neave, Henry R

    2012-01-01

    This book, designed for students taking a basic introductory course in statistical analysis, is far more than just a book of tables. Each table is accompanied by a careful but concise explanation and useful worked examples. Requiring little mathematical background, Elementary Statistics Tables is thus not just a reference book but a positive and user-friendly teaching and learning aid. The new edition contains a new and comprehensive "teach-yourself" section on a simple but powerful approach, now well-known in parts of industry but less so in academia, to analysing and interpreting process dat

  9. Empirical yield tables for Michigan.

    Science.gov (United States)

    Jerold T. Hahn; Joan M. Stelman

    1984-01-01

    Describes the tables derived from the 1980 Forest Survey of Michigan and presents ways the tables can be used. These tables are broken down according to Michigan's four Forest Survey Units, 14 forest types, and 5 site-index classes.

  10. Empirical yield tables for Wisconsin.

    Science.gov (United States)

    Jerold T. Hahn; Joan M. Stelman

    1989-01-01

    Describes the tables derived from the 1983 Forest Survey of Wisconsin and presents ways the tables can be used. These tables are broken down according to Wisconsin`s five Forest Survey Units and 14 forest types.

  11. Permit.LOA table

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table includes the effective dates by vessel and permit number for each issued letter of authorization (LOA) by the Permit Office (APSD)

  12. VMS forms Output Tables

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These output tables contain parsed and format validated data from the various VMS forms that are sent from any given vessel, while at sea, from the VMS devices on...

  13. The Periodic Table CD.

    Science.gov (United States)

    Banks, Alton J.; Holmes, Jon L.

    1995-01-01

    Describes the characteristics of the digitized version of The Periodic Table Videodisc. Provides details about the organization of information and access to the data via Macintosh and Windows computers. (DDR)

  14. Setting the Periodic Table.

    Science.gov (United States)

    Saturnelli, Annette

    1985-01-01

    Examines problems resulting from different forms of the periodic table, indicating that New York State schools use a form reflecting the International Union of Pure and Applied Chemistry's 1984 recommendations. Other formats used and reasons for standardization are discussed. (DH)

  15. Body Mass Index Table

    Science.gov (United States)

    ... Families ( We Can! ) Health Professional Resources Body Mass Index Table 1 for BMI greater than 35, go ... Health Information Email Alerts Jobs and Careers Site Index About NHLBI National Institute of Health Department of ...

  16. Decision table languages and systems

    CERN Document Server

    Metzner, John R

    1977-01-01

    ACM Monograph Series: Decision Table Languages and Systems focuses on linguistic examination of decision tables and survey of the features of existing decision table languages and systems. The book first offers information on semiotics, programming language features, and generalization. Discussions focus on semantic broadening, outer language enrichments, generalization of syntax, limitations, implementation improvements, syntactic and semantic features, decision table syntax, semantics of decision table languages, and decision table programming languages. The text then elaborates on design im

  17. 27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

    Science.gov (United States)

    2010-04-01

    ... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

  18. The 2005 CHF look-up table

    International Nuclear Information System (INIS)

    Groeneveld, D.C.; Vasic, A.Z.; Leung, L.K.H.; Durmayaz, A.; Shan, J.Q.; Yang, J.; Cheng, S.C.

    2005-01-01

    Full text of publication follows: CHF Look-up tables have been used widely for the prediction of the Critical Heat Flux (CHF) The CHF look-up table is basically a normalized data bank. The first CHF look-up table was constructed by Doroshchuk et al. (1975), using a limited database of 5 000 data points. This table, and all subsequent tables, contain normalized CHF values for a vertical 8 mm water-cooled tube for various pressures, mass fluxes and qualities. The CHF table development work has since been in progress at various institutions (e.g. CENG-Grenoble, University of Ottawa (UO), Ottawa, IPPE, Obninsk, and AECL, Chalk River) using an ever increasing data base. The 1995 CHF look-up table employs a data base containing about 30 000 CHF points and provides CHF values for an 8 mm ID, water-cooled tube, for 19 pressures, 20 mass fluxes, and 23 qualities. covering the full range of conditions of practical interest. The 2005 CHF LUT is an update to the 1995 LUT and addresses several concerns raised in the literature. The major improvements made are: - enhancement of the quality of the data base of the CHF look-up table (identify outliers, improve screening procedures); - increase in the data base by adding recently obtained data; - employment of greater subdivision of the look-up table by using smaller intervals in the independent parameters (pressure, mass flux and quality) at conditions where the variation in CHF is significant; - improvement of the smoothness of the CHF look-up table. This was done by the use of logarithmic functions for CHF, using optimum Spline functions etc. A discussion of the impact of these changes on the prediction accuracy and table smoothness is presented. It will be shown that the 2005 CHF look-up table is characterized by a significant improvement in accuracy and smoothness. [1] D. Groeneveld is the corresponding author. He is an Adjunct Professor at the University of Ottawa. (authors)

  19. Reading the Water Table: The Interaction between Literacy Practices and Groundwater Management Training in Preparing Farmers for Climate Change in South India

    Science.gov (United States)

    Chavva, Konda Reddy; Smith, Cristine A.

    2012-01-01

    This article focuses on farmers' use of literacy for individual decision-making on crop-water management and crop choices and investigates how farmer participants perceive the usefulness of Farmer Water School (FWS) training. It draws upon a study conducted with farmers of Kurnool district of Andhra Pradesh, India. This study has demonstrated that…

  20. Empirical yield tables for Minnesota.

    Science.gov (United States)

    Jerold T. Hahn; Gerhard K. Raile

    1982-01-01

    Describes the tables derived from the 1977 Forest Survey of Minnesota and presents examples of how the tables can be used. These tables are broken down according to Minnesota's four Forest Survey Units, 14 forest types, and 5 site index classes. Presents 210 of the 350 possible tables that contained sufficient data to justify publication.

  1. X-ray table

    International Nuclear Information System (INIS)

    Craig, J.R.; Otto, G.W.

    1980-01-01

    An X-ray radiographic or fluoroscopic table is described which includes a film holder with a frame attached to a cable running over end pulleys for positioning the holder longitudinally as desired under the table top. The holder has a front opening to receive a cassette-supporting tray which can be slid out on tracks to change the cassette. A reed switch on the frame is opened by a permanent magnet on the tray only when the tray is half-way out. When the switch is closed, an electromagnet locks the pulley and the holder in place. The holder is thus automatically locked in place not only during exposure (tray in) but when the tray is out for changing the cassette. To re-position the holder, the operator pulls the tray half-out and, using the tray itself, pushes the holder along the table, the holder being counterbalanced by a weight. (author)

  2. Table Tennis Club

    CERN Multimedia

    Table Tennis Club

    2012-01-01

    The CERN Table Tennis club and the Meyrin CTT are organizing two Table Tennis workshops from 2 to 6 July and from 20 to 24 August 2012 inclusive in Meyrin. A professional would be with your children from 14.00 pm to 18.00 pm: an instructor J + S category A. Training courses with specific themes, individual courses would be given depending on the level of the child’s game, “discoveries –table tennis games” courses and games with the robot. Other activities (stretching, relaxation). Afternoons (from 18 to 20 children): 40 CHF per workshop and per child. Evenings (from 18 to 20 adults): 60 CHF per workshop and per adult. For further information, please contact Mr. Monteil : Mobile: (+33) 06 61 31 70 47 E-mail: wilfried.monteil@free.fr.

  3. Periodic table of elements

    International Nuclear Information System (INIS)

    Fluck, E.; Heumann, K.G.

    1985-01-01

    Following a recommendation by the International Union for Pure and Applied Chemistry (IUPAC), the groups of the periodic table shall be numbered from 1 to 18, instead of I to VIII as before. The recommendations has been approved of by the Committee on Nomenclature of the American Chemical Society. The new system abandons the distinction between main groups (a) and auxiliary groups (b), which in the past frequently has been the reason for misunderstandings between European and American chemists, due to different handling. The publishing house VCH Verlagsgesellschaft recently produced a new periodic table that shows the old and the new numbering system together at a glance, so that chemists will have time to get familiar with the new system. In addition the new periodic table represents an extensive data compilation arranged by elements. The front page lists the chemical properties of elements, the back page their physical properties. (orig./EF) [de

  4. Dosimetric Effects Of Different Treatment Tables During Radiotherapy

    International Nuclear Information System (INIS)

    Murkovic, M.; Grego, T.; Bibic, J.

    2015-01-01

    The aim of our study was to measure the effect of mega-voltage photon beam attenuation when treating patients through carbon fibre treatment table with and without the carbon laminate base plate on it. We also examined the ability of XiO treatment planning system in modelling this effect. Direct attenuation measurements were made for two treatment tables, Siemens TxT 550 treatment table with TT-A table top and Elekta Precise table with iBEAM evo table top. On both treatment tables we used Orfit Base Plate (32301). Measurements were taken for two photon energies (6 MV and 18 MV), at two different field sizes (5 x 5 cm 2 and 10 x 10 cm 2 ) and different gantry angles in 50 intervals using stationary water phantom and Farmer type ionization chamber. These values were compared to values calculated in XiO. In order to account for the effect of table and base plate during treatment planning in XiO, customized table and base plate templates were develop in Focal planning system. To construct these customized templates, table and base plate contours as well as respective relative electron density's to water were obtained on CT scanner. The largest attenuation effect was seen for oblique treatment angles using low energy and small field sizes, 6.6 percent for the Elekta table top and 8.4 percent for Siemens table top. In this paper we show that customized table and base plate templates introduced in the patient treatment plan can accurately model the attenuation due to their presence to within 0.3 percent. Since dose modifications due to such carbon fiber accessories can be significant, it can be concluded that introduction of customized table and base plate templates into TPS brings an important improvement to patient treatment planning, and should be included in dose calculations whenever possible. (author).

  5. Efeito de velocidades de rebaixamento do nível freático em diferentes períodos de desenvolvimento da cultura da alface Effect of water table drawdown velocities in different stages of lettuce crop

    Directory of Open Access Journals (Sweden)

    Rafael Mingoti

    2006-03-01

    Full Text Available Através deste trabalho objetivou-se determinar os efeitos do encharcamento do solo nas variáveis fenológicas e na produtividade da cultura da alface, identificar o estádio fenológico em que ocorre a maior diminuição da produtividade e obter uma relação entre a produtividade relativa da cultura e o índice diário de estresse. O delineamento experimental adotado foi inteiramente casualizado, arranjado em esquema fatorial [(3x4+1], com 3 repetições. Os tratamentos consistiram do período de inundação (12, 22 e 32 DAT, de velocidades de rebaixamento do nível freático (30 cm em 24, 48, 72 e 96 horas e uma testemunha, na qual não foi aplicado estresse por elevação do lençol freático. A alface apresentou-se como cultura sensível ao encharcamento; entretanto, não foi possível se definir um valor para o coeficiente de drenagem pois, mesmo com a maior velocidade de rebaixamento testada, ocorreu decréscimo de cerca de 50% da produção. Dentre os três períodos nos quais o estresse causado pela elevação do nível freático foi aplicado, o primeiro foi o que ocasionou maiores perdas. A produtividade das plantas de alface apresentou correlação linear negativa com o índice diário de estresse (IDS.The work had the objectives of determining the effect of water table drawdown velocities on the growth and yield of lettuce crop in a flooded soil, identifying the stage of the crop cycle with the highest reduction in the productivity and obtaining a relation between the crop relative productivity and the daily stress index. The statistical experimental design was completely randomized in factorial scheme [(3 x 4 + 1], with three replications. The water table was lowered at 3 stages of the crop cycle (12, 22 and 32 days after the transplanting, four drawdown velocities (30 cm during 24, 48, 72 and 96 h and a 13 treatment in which stress was not applied with the elevation of the water table. The lettuce presented as a sensible crop to

  6. Naturally-occurring alpha activity

    Energy Technology Data Exchange (ETDEWEB)

    Mayneord, W V

    1960-12-01

    In view of the difficulties of assessing the significance of man-made radioactivity it is important to study for comparison the background of natural radioactivity against which the human race has evolved and lives. It is also important to define the present levels of activity so that it will be possible to detect and study as quickly as possible any changes which may occur owing to the release into the environment of new radioactive materials. Moreover, by the study of the behaviour of natural radioactivity light may be shed upon that of the artificially produced isotopes and a number of analogies traced between the two groups. These concepts have led to studies of naturally-occurring radioactive materials alongside a programme of research into fission products in food, water and air, as well as studies of the metabolism of both sets of materials in the human body. Since the last report there has been a useful increase in our knowledge of natural radioactivity in the biosphere, and its levels relative to the new man-made activities. These studies have necessitated technical developments, particularly in the methods of measuring and identifying alpha-ray emitters, to which group many of the more important natural radioactive materials belong.

  7. Application of the new IAPWS Guideline on the fast and accurate calculation of steam and water properties with the Spline-Based Table Look-Up Method (SBTL) in RELAP-7

    Energy Technology Data Exchange (ETDEWEB)

    Kunick, Matthias; Kretzschmar, Hans-Joachim [Zittau/Goerlitz Univ. of Applied Sciences, Zittau (Germany). Dept. of Technical Thermodynamics; Berry, Ray A.; Martineau, Richard C. [Idaho National Laboratory, Idaho Falls, ID (United States). Nuclear Science and Technology; Gampe, Uwe [Dresden Univ. of Technology (Germany). Chair of Thermal Power Machinery and Plants

    2017-07-15

    The numerical simulation of thermalhydraulic processes in nuclear power plants requires very accurate and extremely fast algorithms for calculating the thermophysical properties of water and steam. In order to provide such algorithms, the International Association for the Properties of Water and Steam (IAPWS) has adopted the new ''IAPWS Guideline on the Fast Calculation of Steam and Water Properties with the Spline-Based Table Look-Up Method (SBTL)''. In this article, the SBTL method is applied to property functions of specific volume and specific internal energy (v,e) based on the scientific formulation IAPWS-95 and the latest IAPWS formulations for transport properties. From the newly generated SBTL functions, thermodynamic and transport properties as well as their derivatives and inverse functions are calculable in the fluid range of state for pressures up to 100 MPa and for temperatures up to 1273 K, including the metastable liquid and the metastable vapor regions. The SBTL functions reproduce the underlying formulations with an accuracy of 10-100 ppm and significantly reduced computing times. The SBTL method has been implemented into the nuclear reactor system safety analysis code RELAP-7 [2] to consider the real fluid behavior of water and steam in a novel 7-equation two-phase flow model.

  8. Code for the steam tables for pure water in visual basic 6.0.; Un codigo para las tablas de vapor para agua pura en visual basic 6.0

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Mahendra P. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2002-07-01

    The thermodynamic data of the water are of extreme importance in all of the branches of science and technology; the facilitate the understanding of the natural Earth processes. Nevertheless, for the electrical industry the water plays a very important role during the generation of electrical energy process. Different heat sources such as coal, oil, natural gas, nuclear fuel or the geothermal heat boil the water that forms the steam used to move the turbines. Consequently, the steam tables (the thermodynamic water data) are vital to model thermal and mass transference and physical-chemical processes during the generation of electrical energy. [Spanish] Los datos termodinamicos del agua son de suma importancia en todas las ramas de la ciencia y tecnologia, ellos facilitan el entendimiento de los procesos naturales de la Tierra. Sin embargo, para la industria electrica el agua juega un papel muy importante durante el proceso de generacion de energia electrica. Diferentes fuentes de calor tales como carbon, aceite, gas natural, combustible nuclear o el calor geotermico calientan el agua que forma el vapor utilizado para mover las turbinas. Luego entonces, las tablas de vapor (los datos termodinamicos de agua) son vitales para modelar transferencia termica y de masa y procesos fisico-quimico durante la generacion energia electrica.

  9. Saline water irrigation for crop production

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A R [Directorate of Water Management Research, Indian Council of Agricultural Research (ICAR), Walmi Complex, P.O. - Phulwari Sharif, Patna (India); [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Singh, S S; Singh, S R [Directorate of Water Management Research, Indian Council of Agricultural Research (ICAR), Walmi Complex, P.O. - Phulwari Sharif, Patna (India)

    2001-05-01

    Salinity is one of agriculture's most complex production problems. Excessive salts from irrigation water or high water tables can severely limit crop production. Years of saline water irrigation on poorly drained soils can eventually make economic crop production impossible. About 10% of all land are affected by salinity problems. They occur in every continent in different proportions, more frequently in arid and semi-arid areas. This paper discusses a range of problems related to use of saline water for crop irrigation.

  10. Saline water irrigation for crop production

    International Nuclear Information System (INIS)

    Khan, A.R.; Singh, S.S.; Singh, S.R.

    2001-05-01

    Salinity is one of agriculture's most complex production problems. Excessive salts from irrigation water or high water tables can severely limit crop production. Years of saline water irrigation on poorly drained soils can eventually make economic crop production impossible. About 10% of all land are affected by salinity problems. They occur in every continent in different proportions, more frequently in arid and semi-arid areas. This paper discusses a range of problems related to use of saline water for crop irrigation

  11. Changes in the water-table altitude of the unconfined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2006 to October 2012.

    Data.gov (United States)

    Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  12. Climate change : transportation table

    International Nuclear Information System (INIS)

    Ogilvie, K.

    1999-01-01

    The Kyoto Protocol sets greenhouse gas (GHG) reduction targets for the post-2000 period. If ratified, Canada will be committed to reduce emissions of GHGs by 6 per cent below 1990 levels during the period 2008-2012. A recommended national strategy is to establish 'issue tables' that will advise the Ministers of Energy and Environment on preferred options to reach the Kyoto target and to identify early actions that can be taken. The 'Transportation Table' which is the focus of this paper, is one of the 15 sectoral tables. The Transportation Table will identify by July 1999, specific measures to mitigate GHG emissions from Canada's transportation sector. Currently, GHG emissions from the transportation sector are predicted to be 27 per cent above 1990 levels by 2010. Fuel taxes, emissions trading, and research into improved vehicle technologies and automotive fuels are some of the recommended options which can help reduce emissions trading from the transportation sector. Studies are underway to deal with emissions from transport in two sub-groups, freight and passenger. 1 fig

  13. Statistical tables 2003

    International Nuclear Information System (INIS)

    2003-01-01

    The energy statistical table is a selection of statistical data for energies and countries from 1997 to 2002. It concerns the petroleum, the natural gas, the coal, the electric power, the production, the external market, the consumption per sector, the energy accounting 2002 and graphs on the long-dated forecasting. (A.L.B.)

  14. Conversion tables. Appendix I

    International Nuclear Information System (INIS)

    McKerrell, H.

    1975-01-01

    Tables are presented for the conversion of standard (5568 year half-life) C-14 dates to calendar years. The major part of the data converts C-14 dates to tree-ring years: additional data are given, based on the Egyptian historical curve. (U.K.)

  15. Submatrices of character tables and basic sets

    DEFF Research Database (Denmark)

    Bessenrodt, Christine; Olsson, Jørn Børling

    2012-01-01

    In this investigation of character tables of nite groups we study basic sets and associated representation theoretic data for complementary sets of conjugacy lasses. For the symmetric groups we nd unexpected properties of characters on restricted sets of conjugacy classes, like beautiful...... combinatorial determinant formulae for submatrices of the character table and Cartan matrices with respect to basic sets; we observe that similar phenomena occur for the transition matrices between power sum symmetric functions to bounded partitions and the k-Schur functions dened by Lapointe and Morse...

  16. Analyzing and Improving the Water-Table Fluctuation Method of Estimating Groundwater Recharge: Field Considerations Patros, T.B. and Parkin, G.W., School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada

    Science.gov (United States)

    Patros, T.; Parkin, G. W.

    2012-12-01

    The focus of the project is on measuring and quantifying groundwater recharge (GWR) using the water-table fluctuation (WTF) method. This method requires measuring the change in water-table (WT) height (Δh) during recharge (R) events and volumetric soil specific yield water content (θsy), (&/or) perhaps more correctly volumetric soil fillable water content (θf). The rise in WT can also result from other non-precipitation-related WTF causes (e.g., Lisse effect, temperature variations, barometric, lateral flow, Reverse Wieringermeer effect, encapsulated air, pumping), which must be counted for. The measurement of the storativity (S) terms (θsy) and/or θf) is, indeed, not clear-cut and often they are taken as being constant with depth, time, WT movement (Drying-Wetting & Freezing-Thawing) history and heterogeneity. In fact, these two terms (θsy & θf) are controversial in their definition, thus in their use, in the literature and may either overestimate the R, when using θsy, or underestimate it, when using θf. To resolve some of these questions, a novel-automated method is under development, at the University of Guelph's Elora Research Station (ERS) and Arboretum, along with a novel multi-event time series model. The long-term expected outcomes and significance of this study are; 1. Establishing accuracy in defining and evaluating the θsy and θf and using them accordingly in estimating GWR with the WTF method in order to overcome some of the existing substantial gaps in our knowledge of groundwater (GW) storage variation. 2. Obtaining GWR measurements at the local scale on a year-round basis, which are currently scarce or even completely lacking for many regions of Ontario and thus would provide a valuable database for guiding development of any policy requiring GWR. 3. Using this database to calibrate and test estimates of the spatial and temporal variability in regional-scale (watershed scale) GWR from approximate statistical techniques or deterministic

  17. Stable isotope and noble gas constraints on the source and residence time of spring water from the Table Mountain Group Aquifer, Paarl, South Africa and implications for large scale abstraction

    Science.gov (United States)

    Miller, J. A.; Dunford, A. J.; Swana, K. A.; Palcsu, L.; Butler, M.; Clarke, C. E.

    2017-08-01

    Large scale groundwater abstraction is increasingly being used to support large urban centres especially in areas of low rainfall but presents particular challenges in the management and sustainability of the groundwater system. The Table Mountain Group (TMG) Aquifer is one of the largest and most important aquifer systems in South Africa and is currently being considered as an alternative source of potable water for the City of Cape Town, a metropolis of over four million people. The TMG aquifer is a fractured rock aquifer hosted primarily in super mature sandstones, quartzites and quartz arenites. The groundwater naturally emanates from numerous springs throughout the cape region. One set of springs were examined to assess the source and residence time of the spring water. Oxygen and hydrogen isotopes indicate that the spring water has not been subject to evaporation and in combination with Na/Cl ratios implies that recharge to the spring systems is via coastal precipitation. Although rainfall in the Cape is usually modelled on orographic rainfall, δ18O and δ2H values of some rainfall samples are strongly positive indicating a stratiform component as well. Comparing the spring water δ18O and δ2H values with that of local rainfall, indicates that the springs are likely derived from continuous bulk recharge over the immediate hinterland to the springs and not through large and/or heavy downpours. Noble gas concentrations, combined with tritium and radiocarbon activities indicate that the residence time of the TMG groundwater in this area is decadal in age with a probable maximum upper limit of ∼40 years. This residence time is probably a reflection of the slow flow rate through the fractured rock aquifer and hence indicates that the interconnectedness of the fractures is the most important factor controlling groundwater flow. The short residence time of the groundwater suggest that recharge to the springs and the Table Mountain Group Aquifer as a whole is

  18. Occurence of thrips on Niagara table grape and its control with the insecticides thiacloprid and methiocarb associated with Metarhizium anisopliae Ocorrência de tripes em uva Niagara e seu controle com os inseticidas thiacloprid e methiocarb associados com Metarhizium anisopliae

    Directory of Open Access Journals (Sweden)

    ROGÉRIO BIAGGIONI LOPES

    2002-04-01

    Full Text Available Thrips are reported as important pests on table grapes in United States and several countries of Europe. Damage caused by thrips, particulary Frankliniella occidentalis, was observed on niagara table grape crop in Limeira-SP, Brazil. During the blooming period, high thrips densities were observed feeding on pollen and small berries. The symptoms left were more visible after the development of the berries and were characterized by dark scars and suberized surface on berries, sometimes causing the berry to crack, and the seed to prolapse. The effect of insecticides thiacloprid or methiocarb, associated or not with the entomopathogenic fungus Metarhizium anisopliae were evaluated during the blooming period. For evaluation of thrips damage on fruits, the treatments were applied three additional times, 7, 14 and 21 days after the first application. The treatments were: a M. anisopliae (strain 1037 1x10(7 conidia/mL; b thiacloprid 20mL/100L; c-d methiocarb 100 and 150mL/100L; e methiocarb 100mL/100L + M. anisopliae 1x10(7 conidia/mL. Only methiocarb, associated or not with the fungus, was effective in reducing thrips infestation, and no phytotoxic damage was observed. The efficiency of methiocarb 150mL/100L and the insecticide associated with the fungus for the control of the thrips population was 84.2 and 95.5%, respectively. In both cases, there was a reduction of approximately 70% in the number of berries with scars symptoms. For control of thrips on table grapes, chemical insecticides associated or not with M. anisopliae should be applied during the blooming period of the crop.Os tripes são mencionados como importantes pragas da cultura da uva de mesa em diversos países da Europa e Estados Unidos. Em área de cultivo da uva Niagara localizada na região de Limeira-SP verificou-se a ocorrência de danos provocados por Frankliniella occidentalis. Essa praga foi observada, principalmente, durante a fase de florescimento, alimentando-se de pólen e

  19. What occurred in the reactors

    International Nuclear Information System (INIS)

    Kudo, Kazuhiko

    2013-01-01

    Described is what occurred in the reactors of Fukushima Daiichi Nuclear Power Plant at the Tohoku earthquake and tsunami (Mar. 11, 2011) from the aspect of engineering science. The tsunami attacked the Plant 1 hr after the quake. The Plant had reactors in buildings no.1-4 at 10 m height from the normal sea level which was flooded by 1.5-5.5 m high wave. All reactors in no.1-6 in the Plant were the boiling water type, and their core nuclear reactions were stopped within 3 sec due to the first quake by control rods inserted automatically. Reactors in no.1-5 lost their external AC power sources by the breakdown and subsequent submergence (no.1-4) of various equipments and in no.1, 2 and 4, the secondary DC power was then lost by the battery death. Although the isolation condenser started to cool the reactor in no.1 after DC cut, its valve was then kept closed to heat up the reactor, leading to the reaction of heated Zr in the fuel tube and water to yield H 2 which was accumulated in the building: the cause of hydrogen explosion on 12th. The reactor in no.2 had the reactor core isolation cooling system (RCIC) which operated normally for few hrs, then probably stopped to heat up the reactor, resulting in meltdown of the core but no explosion occurred because of the opened door of the blowout panel on the wall by the blast of no.1 explosion. The reactor in no.3 had RCIC and high pressure coolant injection system, but their works stopped to result in the core damage and H 2 accumulation leading to the explosion on 14th. The reactor in no.4 had not been operated because of its periodical annual examination, but was explored on 15th, of which cause was thought to be due to backward flow of H 2 from no.3. Finally, the author discusses about this accident from the industrial aspect of the design of safety level (defense in depth) on international views, and problems and tasks given. (T.T.)

  20. Regional analysis of groundwater phosphate concentrations under acidic sandy soils: Edaphic factors and water table strongly mediate the soil P-groundwater P relation.

    Science.gov (United States)

    Mabilde, Lisa; De Neve, Stefaan; Sleutel, Steven

    2017-12-01

    Historic long-term P application to sandy soils in NW-Europe has resulted in abundant sorption, saturation and eventually leaching of P from soil to the groundwater. Although many studies recognize the control of site-specific factors like soil texture and phosphate saturation degree (PSD), the regional-scaled relevance of effects exerted by single factors controlling P leaching is unclear. Very large observational datasets of soil and groundwater P content are furthermore required to reveal indirect controls of soil traits through mediating soil variables. We explored co-variation of phreatic groundwater orthophosphate (o-P) concentration and soil factors in sandy soils in Flanders, Belgium. Correlation analyses were complemented with an exploratory model derived using 'path analysis'. Data of oxalate-extractable Al, Fe, P and pH KCl , phosphate sorption capacity (PSC) and PSD in three depth layers (0-30, 30-60, 60-90 cm), topsoil SOC, % clay and groundwater depth (fluctuation) were interpolated to predict soil properties on exact locations of a very extensive net of groundwater monitoring wells. The mean PSD was only poorly correlated to groundwater o-P concentration, indicating the overriding control of other factors in the transport of P to the groundwater. A significant (P soil pH and groundwater table depth than by PSD indicates the likely oversimplification of the latter index to measure the long-term potential risk of P leaching. Accounting for controls on leaching not included in PSD via an alternative index, however, seems problematic as in Flanders for example groundwater o-P turned out to be higher in finer textured soils or soils with higher pedogenic Fe content, probably because of their lower pedogenic Al content and higher soil pH. Path analysis of extensive soil and groundwater datasets seems a viable way to identify prime local determinants of soil P leaching and could be further on used for 'ground-truthing' more complex P-migration simulation

  1. Modeling the potential impacts of climate change on the water table level of selected forested wetlands in the southeastern United States

    OpenAIRE

    Zhu, Jie; Sun, Ge; Li, Wenhong; Zhang, Yu; Miao, Guofang; Noormets, Asko; McNulty, Steve G.; King, John S.; Kumar, Mukesh; Wang, Xuan

    2017-01-01

    The southeastern United States hosts extensive forested wetlands, providing ecosystem services including carbon sequestration, water quality improvement, groundwater recharge, and wildlife habitat. However, these wetland ecosystems are dependent on local climate and hydrology, and are therefore at risk due to climate and land use change. This study develops site-specific empirical hydrologic models for five forested wetlands with different characteristics by analyzing long-t...

  2. Tomographic examination table

    International Nuclear Information System (INIS)

    Redington, R.W.; Henkes, J.L.

    1979-01-01

    Equipment is described for positioning and supporting patients during tomographic mammography using X-rays. The equipment consists of a table and fabric slings which permit the examination of a downward, pendant breast of a prone patient by allowing the breast to pass through a aperture in the table into a fluid filled container. The fluid has an X-ray absorption coefficient similar to that of soft human tissue allowing high density resolution radiography and permitting accurate detection of breast tumours. The shape of the equipment and the positioning of the patient allow the detector and X-ray source to rotate 360 0 about a vertical axis through the breast. This permits the use of relatively simple image reconstruction algorithms and a divergent X-ray geometry. (UK)

  3. Seashore marine table quiz

    OpenAIRE

    Institute, Marine

    2013-01-01

    Develop an increasing awareness of plants and animals that live in local marine environments including the seashore, seas and oceans of Ireland. After learning all about the seashore and other marine related lessons, this quiz can be used to evaluate the student’s knowledge of the marine related living things and natural environments. The table quiz can be used as a guide, highlighting facts about the marine environment and some of the animals that live there.

  4. Earl occurring and continuing effects

    International Nuclear Information System (INIS)

    Scott, B.R.; Hahn, F.F.

    1989-01-01

    This chapter develops health-risk models for early and continuing effects of exposure to beta or gamma radiation that could be associated with light water nuclear power plant accidents. The main purpose of the chapter is to provide details on each health-risk model and on the data used. Early and continuing effects considered are prodromal symptoms and nonneoplastic diseases that usually occur soon after a brief radiation exposure. These effects are generally associated with relatively high (greater than 1 Gy) absorbed organ doses. For most of the effects considered, there is an absorbed organ dose threshold below which no effects are seen. Some information is provided on health effects observed in victims of the Chernobyl power plant accident. Organs of primary interest, because of their high sensitivity or their potential for receiving large doses, are bone marrow, gastrointestinal tract, thyroid glands, lungs, skin, gonads, and eyes. Exposure of the fetus is also considered. Additional data and modeling techniques available since publication of the Reactor Safety Study were used to obtain models for morbidity and mortality

  5. Table Tennis Club

    CERN Document Server

    Table Tennis Club

    2012-01-01

    2012 CERN Table Tennis Tournament As the campaign launched by the CERN medical service “Move! & Eat better” is designed in particular to encourage people at CERN to take more regular exercise, the CERN Table Tennis Club, with its traditional CERN Table Tennis Tournament is providing an excellent opportunity to practice moving. The tournament will take place at the Meyrin CTT, 2 rue de Livron, Saturday August 25, 2012, in the afternoon (starting at 13:30). It is open to all CERN staff, users, visitors and families, including of course summer students, who are strongly encouraged to participate. In order to register, simply send an E-mail to Jean-Pierre Revol (jean-pierre.revol@cern.ch). You may also find useful information on the Club Web page http://www.cern.ch/tabletennis CERN 2011 champion Savitha Flaecher, between the finalist Bertrand Mouches on her left, the winner of the consolation draw on her right (Sudarshan Paramesvaran), and far left, Denis Moriaud (semi-finalist a...

  6. SRTC - Gap Analysis Table

    International Nuclear Information System (INIS)

    M.L. Johnson

    2005-01-01

    The purpose of this document is to review the existing SRTC design against the ''Nuclear Safety Design Bases for License Application'' (NSDB) [Ref. 10] requirements and to identify codes and standards and supplemental requirements to meet these requirements. If these codes and standards and supplemental requirements can not fully meet these safety requirements then a ''gap'' is identified. These gaps will be identified here and addressed using the ''Site Rail Transfer Cart (SRTC) Design Development Plan'' [Ref. 14]. The codes and standards, supplemental requirements, and design development requirements are provided in the SRTC and associated rails gap analysis table in Appendix A. Because SRTCs are credited with performing functions important to safety (ITS) in the NSDB [Ref. 10], design basis requirements are applicable to ensure equipment is available and performs required safety functions when needed. The gap analysis table is used to identify design objectives and provide a means to satisfy safety requirements. To ensure that the SRTC and rail design perform required safety Functions and meet performance criteria, this portion of the gap analysis table supplies codes and standards sections and the supplemental requirements and identifies design development requirements, if needed

  7. Global Reference Tables Services Architecture

    Data.gov (United States)

    Social Security Administration — This database stores the reference and transactional data used to provide a data-driven service access method to certain Global Reference Table (GRT) service tables.

  8. Aggregation Algorithms in Heterogeneous Tables

    Directory of Open Access Journals (Sweden)

    Titus Felix FURTUNA

    2006-01-01

    Full Text Available The heterogeneous tables are most used in the problem of aggregation. A solution for this problem is to standardize these tables of figures. In this paper, we proposed some methods of aggregation based on the hierarchical algorithms.

  9. TABLE OF CONTENTS TABLE OF CONTENTS

    African Journals Online (AJOL)

    eobe

    Effects of Variability in the Pozzolanic Properties of Rice Husk. Ash on the ... on Semi-Infinite Elastic Soils using Fourier Transform Method. H. N. Onah, N. N. ... Al – Si – Mg Alloy in Simulated Sea Water Environment. S. M. Adams, S. A. Yaro,.

  10. Characterization of calculation of in-situ retardation factors of contaminant transport using naturally-radionuclides and rock/water interaction occurring U-Series disequilibria timescales. 1997 annual progress report

    International Nuclear Information System (INIS)

    Goldstein, S.; Ku, T.L.; Luo, S.; Murrel, M.; Roback, R.

    1997-01-01

    'The research is directed toward a quantitative assessment of contaminant transport rates in fracture-rock systems using uranium-series radionuclides. Naturally occurring uranium-and thorium-series radioactive disequilibria will provide information on the rates of adsorption-desorption and transport of radioactive contaminants as well as on fluid transport and rock dissolution in a natural setting. This study will also provide an improved characterization of preferential flow and contaminant transport at the Idaho Environmental and Engineering Lab. (INEEL) site. To a lesser extent, the study will include rocks in the unsaturated zone. The authors will produce a realistic model of radionuclide migration under unsaturated and saturated field conditions at the INEEL site, taking into account the retardation processes involved in the rock/water interaction. The major tasks are to (1) determine the natural distribution of U, Th, Pa and Ra isotopes in rock minerals. sorbed phases on the rocks, and in fluids from both saturated and unsaturated zones at the site, and (2) study rock/water interaction processes using U/Th series disequilibrium and a statistical analysis-based model for the Geologic heterogeneity plays an important role in transporting contaminants in fractured rocks. Preferential flow paths in the fractured rocks act as a major pathway for transport of radioactive contaminants in groundwaters. The weathering/dissolution of rock by groundwater also influences contaminant mobility. Thus, it is important to understand the hydrogeologic features of the site and their impact on the migration of radioactive contaminants. In this regard, quantification of the rock weathering/dissolution rate and fluid residence time from the observed decay-series disequilibria will be valuable. By mapping the spatial distribution of the residence time of groundwater in fractured rocks, the subsurface preferential flow paths (with high rock permeability and short fluid residence

  11. VIDENTE 1.1: a graphical user interface and decision support system for stochastic modelling of water table fluctuations at a single location; includes documentation of the programs KALMAX, KALTFN, SSD and EMERALD and introductions to stochastic modelling; 2nd rev. ed

    NARCIS (Netherlands)

    Bierkens, M.F.P.; Bron, W.A.; Knotters, M.

    2002-01-01

    A description is given of the program VIDENTE. VIDENTE contains a decision support system to choose between different models for stochastic modelling of water-table depths and a graphical user interface to facilitate operating and running four implemented models: KALMAX, KALTFN, SSD and EMERALD. In

  12. Uranium interaction with soil minerals in the presence of co-contaminants: Case Study- subsurface sediments at or below the water table

    Energy Technology Data Exchange (ETDEWEB)

    Gartman, Brandy N.; Qafoku, Nikolla

    2016-03-09

    Uranium (U) contaminated subsurface systems are common on a global scale mainly because of its essential role in the production of plutonium for nuclear weapons and other nuclear energy and research activities. Studying the behavior and fate of U in these systems is challenging because of heterogeneities of different types (i.e., physical, chemical and mineralogical) and a complex network of often time-dependent hydrological, biological and chemical reactions and processes that occur sequentially or simultaneously, affecting and/or controlling U mobility. A U contaminated site, i.e., the Integrated Field Research Challenge site in Rifle, CO, USA (a former U mill site) is the focus of this discussion. The overall objectives of this chapter are to 1) provide an overview of the contamination levels (U and other co-contaminants) at this field site; 2) review and discuss different aspects of mineral-U contaminant interactions in reduced and oxidized environments, and in the presence of co-contaminants; 3) present results from a systematic macroscopic, microscopic, and spectroscopic study as an example of the current research efforts and the state-of-knowledge in this important research area; and 4) offer insightful conclusive remarks and future research needs about reactions and processes that control U and other contaminants’ fate and behavior under hydraulically saturated conditions. The implications and applications presented in this chapter are valid for U contaminated sites across the world.

  13. Artificial recharge of the water-table aquifer in the latian volcano in Rome province; Ricarica artificiale dalla falda acquifera presente nel vulcano laziale in Provincia di Roma

    Energy Technology Data Exchange (ETDEWEB)

    Bersani, P.; Piotti, A. [Ambito Territoriale Ottimale, Lazio Centrale, Rome (Italy)

    2001-06-01

    The zone of the Latian Volcano extends in an area of about 1.500 km{sup 2} in the south-est of Rome. This area is thickly peopled, owing to the presence of many towns (Velletri, Frascati, Albano, etc.) in the central share of the volcanic edifice. Actually the volcanic edifice of Alban Hills shows in the central and higher area, a large caldera (Tuscolana-Artemisia). This caldera has a sub-circular form wide 10 km in diameter and 75 km{sup 2} in area. The excessive groundwater drawing by wells caused the depauperation of underground resources so to produce a real crisis since 1984. To restore of water balance of the aquifer of the Latian Volcano, an important contribution could be given by the artificial recharge of the higher aquifer. This recharge could be done by allowing to meteoric water to inflitrate as much as possible in the underground by realization of an artificial lake; otherwise by making a series of little infiltration-basins together with infiltration-wells. Besides the realization of the artificial lake could give back to the landscape a characteristic component present in the past centuries until very recent times. [Italian] L'area del Vulcano Laziale si estende su una superficie di circa 1500 km{sup 2} a sud-est di Roma in un'area densamente popolata per la presenza di numerosi centri urbani (Velletri, Frascati, Albano, ecc.), ubicati nella parte centrale dell'ufficio vulcanico. Attualmente l'edificio vulcanico dei Colli Albani presenta in posizione centrale un'ampia caldera sommitale con forma subcircolare, con diametro medio di circa 10 km ed estensione di circa 75 km{sup 2}. Gli eccessivi prelievi di acqua sotterranea hanno condotto ad un impoverimento della risorsa idrica fino a determinare una vera e propria crisi manifestatasi a partire dal 1984. Per riequilibrare il bilancio idrico dell'acquifero del Vulcano Laziale, un contributo significativo potrebbe provenire dalla ricarica artificiale dell

  14. Decompression tables for inside chamber attendants working at altitude.

    Science.gov (United States)

    Bell, James; Thombs, Paul A; Davison, William J; Weaver, Lindell K

    2014-01-01

    Hyperbaric oxygen (HBO2) multiplace chamber inside attendants (IAs) are at risk for decompression sickness (DCS). Standard decompression tables are formulated for sea-level use, not for use at altitude. At Presbyterian/St. Luke's Medical Center (Denver, Colorado, 5,924 feet above sea level) and Intermountain Medical Center (Murray, Utah, 4,500 feet), the decompression obligation for IAs is managed with U.S. Navy Standard Air Tables corrected for altitude, Bühlmann Tables, and the Nobendem© calculator. IAs also breathe supplemental oxygen while compressed. Presbyterian/St. Luke's (0.83 atmospheres absolute/atm abs) uses gauge pressure, uncorrected for altitude, at 45 feet of sea water (fsw) (2.2 atm abs) for routine wound care HBO2 and 66 fsw (2.8 atm abs) for carbon monoxide/cyanide poisoning. Presbyterian/St. Luke's provides oxygen breathing for the IAs at 2.2 atm abs. At Intermountain (0.86 atm abs), HBO2 is provided at 2.0 atm abs for routine treatments and 3.0 atm abs for carbon monoxide poisoning. Intermountain IAs breathe intermittent 50% nitrogen/50% oxygen at 3.0 atm abs and 100% oxygen at 2.0 atm abs. The chamber profiles include a safety stop. From 1990-2013, Presbyterian/St. Luke's had 26,900 total IA exposures: 25,991 at 45 fsw (2.2 atm abs) and 646 at 66 fsw (2.8 atm abs); there have been four cases of IA DCS. From 2008-2013, Intermountain had 1,847 IA exposures: 1,832 at 2 atm abs and 15 at 3 atm abs, with one case of IA DCS. At both facilities, DCS incidents occurred soon after the chambers were placed into service. Based on these results, chamber inside attendant risk for DCS at increased altitude is low when the inside attendants breathe supplemental oxygen.

  15. Exploring the ground ice recharge near permafrost table on the central Qinghai-Tibet Plateau using chemical and isotopic data

    Science.gov (United States)

    Wang, Weihua; Wu, Tonghua; Zhao, Lin; Li, Ren; Zhu, Xiaofan; Wang, Wanrui; Yang, Shuhua; Qin, Yanhui; Hao, Junmin

    2018-05-01

    Thawing permafrost on the Qinghai-Tibet Plateau (QTP) has great impacts on the local hydrological process by way of causing ground ice to thaw. Until now there is little knowledge on ground ice hydrology near permafrost table under a warming climate. This study applied stable tracers (isotopes and chloride) and hydrograph separation model to quantify the sources of ground ice near permafrost table in continuous permafrost regions of the central QTP. The results indicated that the ground ice near permafrost table was mainly supplied by active layer water and permafrost water, accounting for 58.9 to 87.0% and 13.0 to 41.1%, respectively, which implying that the active layer was the dominant source. The contribution rates from the active layer to the ground ice in alpine meadow (59 to 69%) was less than that in alpine steppe (70 to 87%). It showed well-developed hydrogeochemical depth gradients, presenting depleted isotopes and positive chemical gradients with depth within the soil layer. The effects of evaporation and freeze-out fractionation on the soil water and ground ice were evident. The results provide additional insights into ground ice sources and cycling near permafrost table in permafrost terrain, and would be helpful for improving process-based detailed hydrologic models under the occurring global warming.

  16. Study of the oxidation and of the mechanical behavior of irradiated elastomers: consequences of the electronic irradiation on the electrical cables during the occurring of a pressurized water reactor accident

    International Nuclear Information System (INIS)

    Corbin, D.

    2001-01-01

    This thesis contributes to a better understanding and predictions of the consequences of electronic irradiation on the electrical cables when an accident of a pressurized water reactor occurs. We studied the radio-oxidation and the mechanical behaviour of two irradiated elastomers, EPDM (ethylene-propylene-hexadiene 1,4 terpolymer) and hypalon (chloro-sulfonated polyethylene), used respectively as insulating and sheath material of the cable. In the first part, the conditions of exposure to radiation during an accident are presented. They induce a very heterogeneous dose profile in the cable because of the low range of the involved electrons. This situation contrasts with normal operating conditions of the power plant and corresponding qualification tests. In the latter case, the profile is uniform since it is deposited by γ - rays with large ranges. The second part focuses on degradation under presence of oxygen, with typical dose and dose rate conditions for an accident. Thin films of the two elastomers (basic and formulated polymers) are irradiated by electrons and the oxidation products, and their concentrations are determined chemically. The influence, on the kinetics of radio-oxidation, of three parameters typical for the irradiation, the oxygen pressure, the dose rate and the dose is presented there. The effect of antioxidants is studied in the case of EPDM. The third part describes the results concerning the experimental simulation of the dose profile during the accident on thick plates of two formulated elastomers. The evolution of the breaking mechanical properties, as a function of dose and the thickness of the plates, is presented and analysed in correlation with the oxidation profiles. (author)

  17. Radionuclide table. Pt. 1

    International Nuclear Information System (INIS)

    Legrand, Jean; Perolat, J.-P.; Lagoutine, Frederic; Le Gallic, Yves.

    The evaluation of the following 29 radionuclides is presented: 22 Na, 24 Na, sup(24m)Na, 51 Cr, 54 Mn, 57 Co, 58 Co, sup(58m)Co, 60 Co, sup(60m)Co, 75 Se, 103 Ru, sup(103m)Rh, sup(110m)Ag- 110 Ag, 109 Cd, 125 Sb, sup(125mTe), 125 I, 133 Xe, sup(133m)Xe, 131 Cs, 134 Cs, sup(134m)Cs, 139 Ce, 144 Ce- 144 Pr, 144 Pr, 169 Er, 186 Re, 203 Hg. The introduction contains a brief description of radioactive processes and the evaluation rules followed. The best values and associated uncertainties are given for each radionuclide for the major parameters of the decay scheme and the radiation intensities emitted, together with a decay table. Gamma, X-rays and sometimes conversion electron spectra are also provided [fr

  18. Symbol Tables and Branch Tables: Linking Applications Together

    Science.gov (United States)

    Handler, Louis M.

    2011-01-01

    This document explores the computer techniques used to execute software whose parts are compiled and linked separately. The computer techniques include using a branch table or indirect address table to connect the parts. Methods of storing the information in data structures are discussed as well as differences between C and C++.

  19. Oxidation mechanisms occurring in wines

    OpenAIRE

    Oliveira, Carla Maria; Ferreira, António César Silva; Freitas, Victor De; Silva, Artur M. S.

    2011-01-01

    The present review aims to show the state of the art on the oxidation mechanisms occurring in wines, as well as the methods to monitor, classify and diagnose wine oxidation. Wine oxidation can be divided in enzymatic oxidation and non-enzymatic oxidation. Enzymatic oxidation almost entirely occurs in grape must and is largely correlated with the content of hydroxycinnamates, such as caffeoyltartaric acid and paracoumaroyltartaric acid, and flavan-3-ols. Non-enzymatic oxidation, al...

  20. Exigências hídricas da videira na Região do Submédio São Francisco Table grape water requirements in the Submedium São Francisco Region

    Directory of Open Access Journals (Sweden)

    JAQUELINE ÁVILA NETTO

    2000-08-01

    Full Text Available O trabalho objetivou a estimativa das necessidades hídricas da videira (Vitis vinifera L., cv. Itália, sob as condições edafoclimáticas da Região do Submédio São Francisco. A parte experimental foi conduzida no campo experimental de Bebedouro da Embrapa-Centro de Pesquisa Agropecuária do Trópico Semi-Árido, no município de Petrolina, PE, durante o período de maio a agosto de 1996. A evapotranspiração da cultura foi determinada pelo método do balanço hídrico no solo, e a evapotranspiração de referência foi estimada pelo método de Penman, visando avaliar o comportamento do coeficiente de cultura (Kc ao longo do ciclo da cultura. O parreiral, com cinco anos de idade, foi conduzido em sistema de latada a 2 m acima da superfície do solo, num espaçamento de 4 m x 2 m e irrigado diariamente por gotejamento. O consumo hídrico diário máximo da cultura foi de 4,33 mm dia-1, totalizando 333,6 mm no período de observações. Os valores de Kc variaram de 0,50 a 0,74. Determinou-se uma curva característica de Kc para o ciclo vegetativo da videira, a qual permite obter o Kc diário em função dos dias após a poda.This study used data of a field experiment conducted at the Bebedouro experimental base of the Embrapa-Centro de Pesquisa Agropecuária do Trópico Semi-Árido in Petrolina, PE, Brazil, from May to August, 1996, during the growing period of a five-year-old table grape (Vitis vinifera L., Italy cultivar. The plants were conducted in a two-meter above soil surface trellis system, four meters between rows by two meters between plants, and daily irrigated by trickling system. The crop evapotranspiration was determined by the soil water balance method, and the reference evapotranspiration was estimated by the method of Penman, used to analyse the behaviour of the crop coefficient (Kc throughout the crop growing period. The maximum crop daily water use was 4.33 mm d-1 and the total water consumption was 333.6 mm for the whole

  1. Water table and the neutron moisture meter

    Energy Technology Data Exchange (ETDEWEB)

    Visvalingam, M [Hull Univ. (UK). Geography Dept.

    1975-12-01

    Measurements with a neutron moisture meter at Westlands, near Hull, showed count rates at capillary saturation to be within the error limits of count rates at full saturation. However, the saturation profiles in themselves were interesting as they indicated not only the zonation of the soil but also differences in drainable porosity when compared to count-rate profiles at the end of November.

  2. Water Table Recession in Subsurface Drained Soils

    OpenAIRE

    Moustafa, Mahmoud Mohamed; Yomota, Atsushi

    1999-01-01

    Theoretical drainage equations are intensively tested in many parts of humid and arid regions and are commonly used in drainage design. However, this is still a great concern in Japan as the drainage design is exclusively based on local experiences and empirical basis. There is a need therefore to evaluate the theoretical drainage equations under Japanese field conditions to recommend equations for design of subsurface drainage systems. This was the main motivation for this study. While drain...

  3. Use of Decision Tables to Simulate Management in SWAT+

    Directory of Open Access Journals (Sweden)

    Jeffrey G. Arnold

    2018-05-01

    Full Text Available Decision tables have been used for many years in data processing and business applications to simulate complex rule sets. Several computer languages have been developed based on rule systems and they are easily programmed in several current languages. Land management and river–reservoir models simulate complex land management operations and reservoir management in highly regulated river systems. Decision tables are a precise yet compact way to model the rule sets and corresponding actions found in these models. In this study, we discuss the suitability of decision tables to simulate management in the river basin scale Soil and Water Assessment Tool (SWAT+ model. Decision tables are developed to simulate automated irrigation and reservoir releases. A simple auto irrigation application of decision tables was developed using plant water stress as a condition for irrigating corn in Texas. Sensitivity of the water stress trigger and irrigation application amounts were shown on soil moisture and corn yields. In addition, the Grapevine Reservoir near Dallas, Texas was used to illustrate the use of decision tables to simulate reservoir releases. The releases were conditioned on reservoir volumes and flood season. The release rules as implemented by the decision table realistically simulated flood releases as evidenced by a daily Nash–Sutcliffe Efficiency (NSE of 0.52 and a percent bias of −1.1%. Using decision tables to simulate management in land, river, and reservoir models was shown to have several advantages over current approaches, including: (1 mature technology with considerable literature and applications; (2 ability to accurately represent complex, real world decision-making; (3 code that is efficient, modular, and easy to maintain; and (4 tables that are easy to maintain, support, and modify.

  4. Investigation of selected water quality parameters in the Amargosa Drainage Basin

    International Nuclear Information System (INIS)

    Elliott, B.

    1982-08-01

    The purpose of this investigation was to determine whether Amargoso Desert water quality meets established federal drinking water standards. Samples were collected at selected drinking water supply sites and were analyzed for inorganic chemical constituents and radioactivity. The findings indicate that no concentrations of radioactivity in the drinking water exceeded the standards; however, some naturally occurring chemical constituent analysis indicate concentrations above federal drinking water standards. 18 references, 3 figures, 4 tables. (MF)

  5. Volume tables for red alder.

    Science.gov (United States)

    Floyd A. Johnson; R. M. Kallander; Paul G. Lauterbach

    1949-01-01

    The increasing importance of red alder as a commercial species in the Pacific Northwest has prompted the three agencies listed above to pool their tree measurement data for the construction of standard regional red alder volume tables. The tables included here were based on trees from a variety of sites and form classes. Approximately one quarter of the total number of...

  6. MCNPX Model/Table Comparison

    International Nuclear Information System (INIS)

    Hendricks, J.S.

    2003-01-01

    MCNPX is a Monte Carlo N-Particle radiation transport code extending the capabilities of MCNP4C. As with MCNP, MCNPX uses nuclear data tables to transport neutrons, photons, and electrons. Unlike MCNP, MCNPX also uses (1) nuclear data tables to transport protons; (2) physics models to transport 30 additional particle types (deuterons, tritons, alphas, pions, muons, etc.); and (3) physics models to transport neutrons and protons when no tabular data are available or when the data are above the energy range (20 to 150 MeV) where the data tables end. MCNPX can mix and match data tables and physics models throughout a problem. For example, MCNPX can model neutron transport in a bismuth germinate (BGO) particle detector by using data tables for bismuth and oxygen and using physics models for germanium. Also, MCNPX can model neutron transport in UO 2 , making the best use of physics models and data tables: below 20 MeV, data tables are used; above 150 MeV, physics models are used; between 20 and 150 MeV, data tables are used for oxygen and models are used for uranium. The mix-and-match capability became available with MCNPX2.5.b (November 2002). For the first time, we present here comparisons that calculate radiation transport in materials with various combinations of data charts and model physics. The physics models are poor at low energies (<150 MeV); thus, data tables should be used when available. Our comparisons demonstrate the importance of the mix-and-match capability and indicate how well physics models work in the absence of data tables

  7. Qualification of the calculational methods of the fluence in the pressurised water reactors. Improvement of the cross sections treatment by the probability table method; Qualification des methodes de calculs de fluence dans les reacteurs a eau pressurisee. Amelioration du traitement des sections efficaces par la methode des tables de probabilite

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, S H

    1994-01-01

    It is indispensable to know the fluence on the nuclear reactor pressure vessel. The cross sections and their treatment have an important rule to this problem. In this study, two ``benchmarks`` have been interpreted by the Monte Carlo transport program TRIPOLI to qualify the calculational method and the cross sections used in the calculations. For the treatment of the cross sections, the multigroup method is usually used but it exists some problems such as the difficulty to choose the weighting function and the necessity of a great number of energy to represent well the cross section`s fluctuation. In this thesis, we propose a new method called ``Probability Table Method`` to treat the neutron cross sections. For the qualification, a program of the simulation of neutron transport by the Monte Carlo method in one dimension has been written; the comparison of multigroup`s results and probability table`s results shows the advantages of this new method. The probability table has also been introduced in the TRIPOLI program; the calculational results of the iron deep penetration benchmark has been improved by comparing with the experimental results. So it is interest to use this new method in the shielding and neutronic calculation. (author). 42 refs., 109 figs., 36 tabs.

  8. Groundwater table rise in northwest Nile Delta:Problems and Recommendations

    International Nuclear Information System (INIS)

    El-Sayed, S. A.; Atta, E. R.; Al-Ashri, K. M.

    2012-01-01

    The present research work is devoted to evaluate the surrounding zones of a site which could be selected for construction of radiation facility. It is a model study to investigate the factors that protect sites from the risks of groundwater rising. The study area (village 17 and the related cultivated lands) lies in Bangar El Sukar area, south Alexandria Governorate. The area is suffering from the groundwater table rise phenomenon and its relevant problems (water logging, soil salinization and degradation of buildings). This water table rise is investigated using the hydrogeological, hydrogeochemical and isotopic approaches. The groundwater table of the Pleistocene-Holocene aquifer rises due to uncontrolled irrigation and drainage systems and the lack of municipal sewage system as well as soil and aquifer characteristics. The aquifer is being shallow and exists under semi-confined conditions. It consists of heterogeneous deposits (very fine to coarse grained sand, clay and calcareous rock fragments). Depths to water vary between 0.85 m and 1.44 m from ground surface. The groundwater (TDS 3331 mg/l, averagely) is a mixture of both the fresh water of the irrigation canals (TDS = 544.2 mg/l) and the more saline water (TDS = 5505 mg/l, averagely) of the drains used in irrigation. Nile water is considered the main recharge source to these types of waters. The recharge to the aquifer occurs by seepage from the canals and/or by the infiltration of the return flow after irrigation. The infiltration rate is moderately rapid (ranging from 1.8 mm/min to 2.6 mm/min). The groundwater moves from south to north with an average hydraulic gradient reaching about 1.7 x 10-3. The average rate of groundwater flow through the aquifer varies between 1799 m2/day and 543.65 m2/day. In order to avoid the risks related to the problem and its environmental impacts, proper recommendations are presented. Suggested design for a constructed net of drainage system and pumped well is presented in

  9. Disponibilidade de água em pomar de citros submetido a poda e subsolagem em latossolo amarelo dos tabuleiros costeiros Water availability in citros orchard, under prunning and subsoiling, on yellow latosol of coastal table land

    Directory of Open Access Journals (Sweden)

    Laercio Duarte Souza

    2004-04-01

    Full Text Available Um pomar de laranja 'Baianinha' enxertada sobre limão 'Cravo' com 10 anos de idade, recebeu, neste período, práticas culturais de roçadeira no inverno e grade no verão, com três capinas manuais na linha por ano. Instalado em Latossolo Amarelo, nos Tabuleiros Costeiros, apresentava problemas de fitossanidade e produtividade, oriundos do impedimento ao desenvolvimento de raízes e exploração do solo e da água, ocasionados pelas camadas coesas características destes solos. Com o objetivo de aumentar a disponibilidade de água no solo para as plantas, aplicaram-se tratamentos de subsolagem, em interação com diferentes sistemas de poda da parte aérea. Realizaram-se uma amostragem de parâmetros físicos e químicos do solo, e um monitoramento da água nas profundidades de 0,30; 0,50; 0,70; 0,90; 1,10; 1,30 e 1,50 m com sonda de nêutrons, no período de dois anos ( 1º março/96 a 1º março/98, com duas repetições, em leituras semanais. As melhores respostas foram obtidas com os tratamentos subsolados sem poda e com poda leve. O tratamento subsolado com poda brusca apresentou as maiores deficiências de água disponível no solo, superando, inclusive, a testemunha.A ten years old orchard of orange 'Baianinha' grafted on lemon 'Cravo' was submitted, to cultural practices of mower in the winter and grating in the summer, with three hand weedings, within crop line, a year. The work was carried out in a Yellow Latosol in the Coastal Table Land ecosystem. The orchard presented phytopathological and production problems, which were attributed to the impediment of the development of roots and storage of water, caused by the cohesive layers, characteristics of these soils. This study was to increase the water availability to the plants by treatments with subsoiling combined with different pruning systems. Physical and chemical parameters of the soil were evaluated and the behavior of the water, in the depths of 0,30; 0,50; 0,70; 0,90; 1,10; 1

  10. MCNPX Model/Table Comparison

    CERN Document Server

    Hendricks, J S

    2003-01-01

    MCNPX is a Monte Carlo N-Particle radiation transport code extending the capabilities of MCNP4C. As with MCNP, MCNPX uses nuclear data tables to transport neutrons, photons, and electrons. Unlike MCNP, MCNPX also uses (1) nuclear data tables to transport protons; (2) physics models to transport 30 additional particle types (deuterons, tritons, alphas, pions, muons, etc.); and (3) physics models to transport neutrons and protons when no tabular data are available or when the data are above the energy range (20 to 150 MeV) where the data tables end. MCNPX can mix and match data tables and physics models throughout a problem. For example, MCNPX can model neutron transport in a bismuth germinate (BGO) particle detector by using data tables for bismuth and oxygen and using physics models for germanium. Also, MCNPX can model neutron transport in UO sub 2 , making the best use of physics models and data tables: below 20 MeV, data tables are used; above 150 MeV, physics models are used; between 20 and 150 MeV, data t...

  11. Analysis of underlying and multiple-cause mortality data: the life table methods.

    Science.gov (United States)

    Moussa, M A

    1987-02-01

    The stochastic compartment model concepts are employed to analyse and construct complete and abbreviated total mortality life tables, multiple-decrement life tables for a disease, under the underlying and pattern-of-failure definitions of mortality risk, cause-elimination life tables, cause-elimination effects on saved population through the gain in life expectancy as a consequence of eliminating the mortality risk, cause-delay life tables designed to translate the clinically observed increase in survival time as the population gain in life expectancy that would occur if a treatment protocol was made available to the general population and life tables for disease dependency in multiple-cause data.

  12. Analysis of uncertainties, associated to the calculating hypothesis, in discharge tables for high flows estimating, based on mathematics models for calculating water surface profiles fore steady gradually varied flow; Analisis de las incertidumbres, asociadas a las hipotesis de calculo, en la estimacion de curvas de gasto para crcidas, basada en el empleo de modelo matematico de calculo hidraulico en regimen permanente

    Energy Technology Data Exchange (ETDEWEB)

    Aldana Valverde, A. L.; Gonzalez Rodriguez, J. C.

    1999-08-01

    In this paper are analyzed some of the most important factors which can influence on the results of calculating water surface profiles for steady gradually varied flow. In this case, the objective of this kind of modeling, has been the estimation of discharges tables for high flows of river station gages connected to the hydrologic automatic information system (SAIH) of the Confederacion Hidrografica del Sur de Espana, system named red Hidrosur. (Author) 3 refs

  13. Naturally occurring radionuclides in food

    International Nuclear Information System (INIS)

    Djujic, I.

    1995-01-01

    The naturally occurring radionuclides are the major source of radiation exposure to humans. The principal way of natural radiation exposure is the inhalation of 222 Rn decay products (about 85% of the total). The remainder is equally divided between internally deposited radionuclides, cosmic and terrestrial sources. In the present study, the content of 40 K, 210 Pb, 226 Ra, 230 Th, 232 Th and 238 U in representative food samples (milk, pork, beef, potatoes, wheat and corn flour) and samples of different food items that do not represent entire national production but provide interesting additional data for approximative calculation of naturally occurring radionuclide intake is presented. Daily weight of food eaten, participation of food groups, as well as daily intake by food of mentioned naturally occurring radionuclides in the Serbian diet was obtained on the base of house hold budget surveys. The result obtained for daily intake estimates in mBq for Serbian population are 78.1 ( 40 K), 38.2( 210 Pb), 52.3( 226 Ra), 2.0( 230 Th) and 12.5( 238 U). (author)

  14. Elekta Precise Table characteristics of IGRT remote table positioning

    International Nuclear Information System (INIS)

    Riis, Hans L.; Zimmermann, Sune J.

    2009-01-01

    Cone beam CT is a powerful tool to ensure an optimum patient positioning in radiotherapy. When cone beam CT scan of a patient is acquired, scan data of the patient are compared and evaluated against a reference image set and patient position offset is calculated. Via the linac control system, the patient is moved to correct for position offset and treatment starts. This procedure requires a reliable system for movement of patient. In this work we present a new method to characterize the reproducibility, linearity and accuracy in table positioning. The method applies to all treatment tables used in radiotherapy. Material and methods. The table characteristics are investigated on our two recent Elekta Synergy Platforms equipped with Precise Table installed in a shallow pit concrete cavity. Remote positioning of the table uses the auto set-up (ASU) feature in the linac control system software Desktop Pro R6.1. The ASU is used clinically to correct for patient positioning offset calculated via cone beam CT (XVI)-software. High precision steel rulers and a USB-microscope has been used to detect the relative table position in vertical, lateral and longitudinal direction. The effect of patient is simulated by applying external load on the iBEAM table top. For each table position an image is exposed of the ruler and display values of actual table position in the linac control system is read out. The table is moved in full range in lateral direction (50 cm) and longitudinal direction (100 cm) while in vertical direction a limited range is used (40 cm). Results and discussion. Our results show a linear relation between linac control system read out and measured position. Effects of imperfect calibration are seen. A reproducibility within a standard deviation of 0.22 mm in lateral and longitudinal directions while within 0.43 mm in vertical direction has been observed. The usage of XVI requires knowledge of the characteristics of remote table positioning. It is our opinion

  15. The Periodic Table in Croatia

    Directory of Open Access Journals (Sweden)

    Raos, N.

    2011-12-01

    Full Text Available The Croatian (Yugoslav Academy of Sciences and Arts was the first academy to elect D. I. Mendeleev as its honorary member (1882, whereas the periodic table of the elements has been taught regularly at the Zagreb University since 1888. The early interest of Croatian chemists in the periodic table should be attributed primarily to their pan-Slavic attitude, particularly as proof that Slavic people were able to produce "their own Newtons" (M. V. Lomonosov and D. I. Mendeleev. Such enthusiastic views, however, did not help in analyzing the contribution of Mendeleev and other scientists to the discovery and development of the periodic table of the elements.

  16. Preferential flow occurs in unsaturated conditions

    Science.gov (United States)

    Nimmo, John R.

    2012-01-01

    Because it commonly generates high-speed, high-volume flow with minimal exposure to solid earth materials, preferential flow in the unsaturated zone is a dominant influence in many problems of infiltration, recharge, contaminant transport, and ecohydrology. By definition, preferential flow occurs in a portion of a medium – that is, a preferred part, whether a pathway, pore, or macroscopic subvolume. There are many possible classification schemes, but usual consideration of preferential flow includes macropore or fracture flow, funneled flow determined by macroscale heterogeneities, and fingered flow determined by hydraulic instability rather than intrinsic heterogeneity. That preferential flow is spatially concentrated associates it with other characteristics that are typical, although not defining: it tends to be unusually fast, to transport high fluxes, and to occur with hydraulic disequilibrium within the medium. It also has a tendency to occur in association with large conduits and high water content, although these are less universal than is commonly assumed. Predictive unsaturated-zone flow models in common use employ several different criteria for when and where preferential flow occurs, almost always requiring a nearly saturated medium. A threshold to be exceeded may be specified in terms of the following (i) water content; (ii) matric potential, typically a value high enough to cause capillary filling in a macropore of minimum size; (iii) infiltration capacity or other indication of incipient surface ponding; or (iv) other conditions related to total filling of certain pores. Yet preferential flow does occur without meeting these criteria. My purpose in this commentary is to point out important exceptions and implications of ignoring them. Some of these pertain mainly to macropore flow, others to fingered or funneled flow, and others to combined or undifferentiated flow modes.

  17. Automation of BESSY scanning tables

    International Nuclear Information System (INIS)

    Hanton, J.; Kesteman, J.

    1981-01-01

    A micro processor M6800 is used for the automation of scanning and premeasuring BESSY tables. The tasks achieved by the micro processor are: 1. control of spooling of the four asynchronous film winding devices and switching on and off the 4 projections lamps, 2. pre-processing of the data coming from a bi-polar coordinates measuring device, 3. bi-directional interchange of informations between the operator, the BESSY table and the DEC PDP 11/34 mini computer controling the scanning operations, 4. control of the magnification on the table by swapping the projection lenses of appropriate focal lengths and the associated light boxes (under development). In connection with point 4, study is being made for the use of BESSY tables for accurate measurements (+/-5 microns), by encoding the displacements of the projections lenses. (orig.)

  18. The Table Mountain Field Site

    Data.gov (United States)

    Federal Laboratory Consortium — The Table Mountain Field Site, located north of Boulder, Colorado, is designated as an area where the magnitude of strong, external signals is restricted (by State...

  19. The redoubtable ecological periodic table

    Science.gov (United States)

    Ecological periodic tables are repositories of reliable information on quantitative, predictably recurring (periodic) habitat–community patterns and their uncertainty, scaling and transferability. Their reliability derives from their grounding in sound ecological principle...

  20. Table 1: Biofuels simulation scenarios

    Data.gov (United States)

    U.S. Environmental Protection Agency — A spreadsheet containing information used to generate Table 1. Agricultural Market sector results presented in the spreadsheet were generated elsewhere (non-EPA) and...

  1. NNDSS - Table I. infrequently reported notifiable diseases

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table I. infrequently reported notifiable diseases - 2016. In this Table, provisional* cases of selected† infrequently reported notifiable diseases...

  2. Culture of microalgae biomass for valorization of table olive processing water; Cultivo de biomasa de microalgas para la valorización del agua de elaboración de las aceitunas de mesa

    Energy Technology Data Exchange (ETDEWEB)

    Contreras, C.G.; Serrano, A.; Ruiz-Filippi, G.; Borja, R.; Fermoso, F.G.

    2016-07-01

    Table olive processing water (TOPW) contains many complex substances, such as phenols, which could be valorized as a substrate for microalgae biomass culture. The aim of this study was to assess the capability of Nannochloropsis gaditana to grow in TOPW at different concentrations (10- 80%) in order to valorize this processing water. Within this range, the highest increment of biomass was determined at percentage of 40% of TOPW, reaching an increment of 0.36 ± 0.05 mg volatile suspended solids (VSS)/L. Components of algal biomass were similar for the experiments at 10-40% of TOPW, where proteins were the major compounds (56-74%). Total phenols were retained in the microalgae biomass (0.020 ± 0.002 g of total phenols/g VSS). Experiments for 80% of TOPW resulted in a low production of microalgae biomass. High organic matter, nitrogen, phosphorus and phenol removal were achieved in all TOPW concentrations. Although high-value products, such as proteins, were obtained and high removal efficiencies of nutrients were determined, microalgae biomass culture should be enhanced to become a suitable integral processing water treatment. [Spanish] El agua resultante del proceso de elaboración de la aceituna de mesa (TOPW) presenta un elevado contenido en sustancias complejas, como fenoles, que podría permitir su uso como sustrato para el cultivo de microalgas. El objetivo de este estudio se centra en evaluar la capacidad de crecimiento de annochloropsis gaditana en TOPW a distintas concentraciones (10-80%) con vistas a la valorización de estas aguas. El mayor incremento de biomasa se obtuvo para un porcentaje del 40% de TOPW, alcanzando un aumento de 0.36 ± 0.50 mg sólidos en suspensión volátiles (SSV)/L. Los componentes presentes en la biomasa han sido similares para los experimentos con 10-40% de TOPW, siendo las proteínas los compuestos mayoritarios en todos los casos (56-74%). Los fenoles totales quedaron retenidos en las microalgas, alcanzando una concentraci

  3. Naturally occurring methyl salicylate glycosides.

    Science.gov (United States)

    Mao, Ping; Liu, Zizhen; Xie, Meng; Jiang, Rui; Liu, Weirui; Wang, Xiaohong; Meng, Shen; She, Gaimei

    2014-01-01

    As an important part of non steroids anti-inflammation drug (NSAIDs), salicylate has developed from natural substance salicylic acid to natrium salicylicum, to aspirin. Now, methyl salicylate glycoside, a new derivative of salicylic acid, is modified with a -COOH group integrated one methyl radical into formic ether, and a -OH linked with a monosaccharide, a disaccharide or a trisaccharide unit by glycosidic linkage. It has the similar pharmacological activities, anti-inflammatory, analgesic, antipyretic and antithrombotic as the previous salicylates' without resulting in serious side effects, particularly the gastrointestinal toxicity. Owing to the superiority of those significant bioactivities, methyl salicylate glycosides have became a hot research area in NSAIDs for several years. This paper compiles all 9 naturally occurring methyl salicylate glycosides, their distribution of the resource and pharmacological mechanism, which could contribute to the new drug discovery.

  4. Natural occurring radioactive substances. Vol. 1

    Energy Technology Data Exchange (ETDEWEB)

    Emara, A E [National Center for radiation Research and Technology Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    Naturally occurring radioactive substances produced by cosmic rays of those of terrestrial origin are surveyed. The different radioactive decay series are discussed. Special emphasis is given to the element radium as regards its properties and distribution in different environmental samples. The properties of naturally occurring k-40 and its distribution in different natural media are also outlined. Induced radionuclides which are formed as a result of the interaction of cosmic rays with the constituents of the atmosphere are mentioned. In this respect the intensity of natural background radiation and the dose at different locations and levels is surveyed. Some regions of exceptionally high radioactivity which result in high exposure rates are mentioned. Monazite deposits and water springs are mentioned in some detail. The Oklo phenomenon as a natural reactor is also discussed. 8 tabs.

  5. Natural occurring radioactive substances. Vol. 1

    International Nuclear Information System (INIS)

    Emara, A.E.

    1996-01-01

    Naturally occurring radioactive substances produced by cosmic rays of those of terrestrial origin are surveyed. The different radioactive decay series are discussed. Special emphasis is given to the element radium as regards its properties and distribution in different environmental samples. The properties of naturally occurring k-40 and its distribution in different natural media are also outlined. Induced radionuclides which are formed as a result of the interaction of cosmic rays with the constituents of the atmosphere are mentioned. In this respect the intensity of natural background radiation and the dose at different locations and levels is surveyed. Some regions of exceptionally high radioactivity which result in high exposure rates are mentioned. Monazite deposits and water springs are mentioned in some detail. The Oklo phenomenon as a natural reactor is also discussed. 8 tabs

  6. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  7. Mathematical tables tables of in g [z] for complex argument

    CERN Document Server

    Abramov, A A

    1960-01-01

    Mathematical Tables of In ? (z) for Complex Argument is a compilation of tables of In ? (z), z = x + iy, calculated for steps in x and y of 0.01 and with an accuracy of one unit in the last (the sixth) decimal place. Interpolation is used to calculate In ? (z) for intermediate values and is carried out separately for the real and imaginary parts of In ? (z). Six places are retained in interpolation.This book first explains how the values of In ? (z) are calculated using the asymptotic formula in a wide lattice with step h = 0.16, and how the tables and the nomograph are used. The values in the

  8. Does overtraining occur in triathletes?

    Directory of Open Access Journals (Sweden)

    I Margaritis

    2003-06-01

    Full Text Available 1. Objective: Long distance triathlon training is characterized by considerably high volume training loads. This volume can provoke an overtraining state. The aim of the study was to determine whether overtraining occurs in well-trained male triathletes in relation with their volume training loads. 2. Experimental design: A questionnaire investigation was completed two days before the Nice long-distance triathlon (October 1995: 4-km swim, 120-km bike ride and 30-km run. 3. Participants: Ninety-three well-trained male triathletes who took part in the triathlon race. 4. Measures: A questionnaire to relate clinical symptoms, which are known to appear in case of overtraining, was collected. 5. Results: 39.8% of the questioned triathletes reported a decrease in triathlon performances within the last month preceding the race. Moreover, these triathletes exhibited significantly more overtraining-relied symptoms than the others (5.9±3.8 vs 3.4±2.6, P<0.05. Surprisingly, the occurrence of overtraining in triathletes appears not to depend on the volume training loads. 6. Conclusions: These results suggest that overtraining has to be considered in the case of triathletes. This preliminary study evidences the need for further investigation in order to monitor triathletes training respond and prevent overtraining.

  9. Naturally occurring ω-Hydroxyacids.

    Science.gov (United States)

    Wertz, P W

    2018-02-01

    ω-Hydroxyacids are fatty acids bearing a hydroxyl group on the terminal carbon. They are found in mammals and higher plants and are often involved in providing a permeability barrier, the primary purpose of which is to reduce water loss. Some ω-hydroxyacid derivatives may be involved in waterproofing and signalling. The purpose of this review was to survey the known natural sources of ω-hydroxyacids. ω-Hydroxyacids are produced by two different P450-dependent mechanisms. The longer (30-34 carbons) ω-hydroxyacids are produced by chain extension from palmitic acid until the chain extends across the membrane in which the extension is taking place, and then the terminal carbon is hydroxylated. Shorter fatty acids can be hydroxylated directly to produce C16 and C18 ω-hydroxyacids found in plants and 20-eicosatetraenoic acid (20-HETE) by a different P450. The C16 and C18 ω-hydroxyacids are components of polymers in plants. The long-chain ω-hydroxyacids are found in epidermal sphingolipids, in giant-ring lactones from the sebum of members of the equidae, as a component of meibum and in carnauba wax and wool wax. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  10. Monthly tables of measurements. October 2000; Tableaux mensuels des mesures. Octobre 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-01

    This report of the O.P.R.I. (Office of Protection against Ionizing Radiations) exposes the principal results concerning the routine monitoring of environmental radioactivity in France: atmospheric dusts, rainwater, surface water, underground water, sewage water, drinking water, food chain (milk, vegetables, fishes), sea water around nuclear sites and other sites. The activities of various radioisotopes are presented in tables. (N.C.)

  11. Characteristics of Tables for Disseminating Biobehavioral Results.

    Science.gov (United States)

    Schneider, Barbara St Pierre; Nagelhout, Ed; Feng, Du

    2018-01-01

    To report the complexity and richness of study variables within biological nursing research, authors often use tables; however, the ease with which consumers understand, synthesize, evaluate, and build upon findings depends partly upon table design. To assess and compare table characteristics within research and review articles published in Biological Research for Nursing and Nursing Research. A total of 10 elements in tables from 48 biobehavioral or biological research or review articles were analyzed. To test six hypotheses, a two-level hierarchical linear model was used for each of the continuous table elements, and a two-level hierarchical generalized linear model was used for each of the categorical table elements. Additionally, the inclusion of probability values in statistical tables was examined. The mean number of tables per article was 3. Tables in research articles were more likely to contain quantitative content, while tables in review articles were more likely to contain both quantitative and qualitative content. Tables in research articles had a greater number of rows, columns, and column-heading levels than tables in review articles. More than one half of statistical tables in research articles had a separate probability column or had probability values within the table, whereas approximately one fourth had probability notes. Authors and journal editorial staff may be generating tables that better depict biobehavioral content than those identified in specific style guidelines. However, authors and journal editorial staff may want to consider table design in terms of audience, including alternative visual displays.

  12. 30 CFR 250.1401 - Index table.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Index table. 250.1401 Section 250.1401 Mineral... OPERATIONS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf (OCS) Civil Penalties § 250.1401 Index table. The following table is an index of the sections in this subpart: § 250.1401Table Definitions...

  13. The Alfonsine tables of Toledo

    CERN Document Server

    Chabás, José

    2003-01-01

    The Alfonsine Tables of Toledo is for historians working in the fields of astronomy, science, the Middle Ages, Spanish and other Romance languages. It is also of interest to scholars interested in the history of Castile, in Castilian-French relations in the Middle Ages and in the history of patronage. It explores the Castilian canons of the Alfonsine Tables and offers a study of their context, language, astronomical content, and diffusion. The Alfonsine Tables of Toledo is unique in that it: includes an edition of a crucial text in history of science; provides an explanation of astronomy as it was practiced in the Middle Ages; presents abundant material on early scientific language in Castilian; presents new material on the diffusion of Alfonsine astronomy in Europe; describes the role of royal patronage of science in a medieval context.

  14. Statistical probability tables CALENDF program

    International Nuclear Information System (INIS)

    Ribon, P.

    1989-01-01

    The purpose of the probability tables is: - to obtain dense data representation - to calculate integrals by quadratures. They are mainly used in the USA for calculations by Monte Carlo and in the USSR and Europe for self-shielding calculations by the sub-group method. The moment probability tables, in addition to providing a more substantial mathematical basis and calculation methods, are adapted for condensation and mixture calculations, which are the crucial operations for reactor physics specialists. However, their extension is limited by the statistical hypothesis they imply. Efforts are being made to remove this obstacle, at the cost, it must be said, of greater complexity

  15. 7 CFR 457.149 - Table grape crop insurance provisions.

    Science.gov (United States)

    2010-01-01

    ... grown for commercial sale for human consumption as fresh fruit on acreage where the cultural practices... determine the minimum quality grade will be: (i) The United States Standards for Grades of Table Grapes...; (6) Earthquake; (7) Volcanic eruption; or (8) Failure of irrigation water supply, if caused by an...

  16. Breakdown concepts for contingency tables

    NARCIS (Netherlands)

    Kuhnt, S.

    2010-01-01

    Loglinear Poisson models are commonly used to analyse contingency tables. So far, robustness of parameter estimators as well as outlier detection have rarely been treated in this context. We start with finite-sample breakdown points. We yield that the breakdown point of mean value estimators

  17. Steam table routines for the simulation of nuclear power plants

    International Nuclear Information System (INIS)

    Hall, C.A.; Mutafelija, B.A.; Rapp, J.P.

    1976-01-01

    The dynamic simulation of nuclear power generating stations requires evaluation of a large number of steam and water properties at every integration time step. Some of the interpolation/approximation methods presently used are described with particular emphasis on the use of the bilinear transfinite interpolation method. The fundamental requirements for the steam table routines are outlined and different approaches are compared. The superiority of the bilinear transfinite interpolation method is discussed. The use of the steam table functions in real-time simulation is of particular interest

  18. Sled Tests Using the Hybrid III Rail Safety ATD and Workstation Tables for Passenger Trains

    Science.gov (United States)

    2017-08-01

    The Hybrid III Rail Safety (H3-RS) anthropomorphic test device (ATD) is a crash test dummy developed in the United Kingdom to evaluate abdomen and lower thorax injuries that occur when passengers impact workstation tables during train accidents. The ...

  19. Saline-water intrusion related to well construction in Lee County, Florida

    Science.gov (United States)

    Boggess, Durward Hoye; Missimer, T.M.; O'Donnell, T. H.

    1977-01-01

    Ground water is the principle source of water supply in Lee County, Florida where an estimated 30,000 wells have been drilled since 1990. These wells ranges in depth from about 10 to 1,240 feet and tap the water table aquifer or one or more of the artesian water-bearing units or zones in the Tamiami Formation, the upper part of the Hawthorn Formation, the lower part of the Hawthorn Formation and the Tampa Limestone and the Suwannee Limestone. Before 1968, nearly all wells were constructed with galvanized or black iron pipe. Many of these wells are sources of saline-water intrusion into freshwater-bearing zones. The water-bearing zones in the lower part of the Hawthorn Formation, Tampa Limestone, and Suwannee Limestone are artesian-they have higher water levels and usually contain water with a higher concentration of dissolved solids than do the aquifers occurring at shallower depths. The water from these deeper aquifers generally range in dissolved solids concentration from about 1,500 to 2,400 mg/L, and in chloride from about 500 to 1,00 mg/L. A maximum chloride concentration of 15,200 mg/L has been determined. Few of the 3,00 wells estimated to have been drilled to these zones contain sufficient casing to prevent upward flow into overlaying water-bearing zones. Because of water-level differentials, upward movement and lateral intrusion of saline water occurs principally into the upper part of the Hawthorn Formation where the chloride concentrations in water unaffected by saline-water intrusion ranges from about 80 to 150 mg/L. Where intrusion from deep artesian zones has occurred, the chloride concentration in water from the upper part of the Hawthorn Formation ranges from about 300 to more than 2,100 mg/L Surface discharges of the saline water from wells tapping the lower part of the Hawthorn Formation and the Suwannee Limestone also had affected the water-table aquifer which normally contains water with 10 to 50 mg/L of chloride. In one area, the chloride

  20. Differential dormancy of co-occurring copepods

    Science.gov (United States)

    Ohman, Mark D.; Drits, Aleksandr V.; Elizabeth Clarke, M.; Plourde, Stéphane

    1998-08-01

    Four species of planktonic calanoid copepods that co-occur in the California Current System ( Eucalanus californicus Johnson, Rhincalanus nasutus Giesbrecht, Calanus pacificus californicus Brodsky, and Metridia pacifica Brodsky) were investigated for evidence of seasonal dormancy in the San Diego Trough. Indices used to differentiate actively growing from dormant animals included developmental stage structure and vertical distribution; activity of aerobic metabolic enzymes (Citrate Synthase and the Electron Transfer System complex); investment in depot lipids (wax esters and triacylglycerols); in situ grazing activity from gut fluorescence; and egg production rates in simulated in situ conditions. None of the 4 species exhibited a canonical calanoid pattern of winter dormancy - i.e., synchronous developmental arrest as copepodid stage V, descent into deep waters, reduced metabolism, and lack of winter reproduction. Instead, Calanus pacificus californicus has a biphasic life history in this region, with an actively reproducing segment of the population in surface waters overlying a deep dormant segment in winter. Eucalanus californicus is dormant as both adult females and copepodid V's, although winter females respond relatively rapidly to elevated food and temperature conditions; they begin feeding and producing eggs within 2-3 days. Rhincalanus nasutus appears to enter dormancy as adult females, although the evidence is equivocal. Metridia pacifica shows no evidence of dormancy, with sustained active feeding, diel vertical migration behavior, and elevated activity of metabolic enzymes in December as well as in June. The four species also differ markedly in water content, classes of storage lipids, and specific activity of Citrate Synthase. These results suggest that copepod dormancy traits and structural composition reflect diverse adaptations to regional environmental conditions rather than a uniform, canonical series of traits that remain invariant among taxa

  1. Superconductivity and the Periodic Table

    International Nuclear Information System (INIS)

    Chapnik, I.M.

    1985-01-01

    In view of the inability of the present theory of superconductivity to make reliable predictions for the magnitude of Tsub(c) it seems useful to search for empirical relationships between the composition of the compound and the Tsub(c) value. Table I gives a list of the available Tsub(c) data for transition metals (TM) having from 3 to 9 outer electrons and Tsub(c) data for non-transition elements (NTE) of groups IIB, IIIB and IVB, including data for amorphous (Am) structures and structures (marked by triangles) obtained at high pressures. The analogous metals have therefore the same structure. In Tables II to IV the Tsub(c) data are presented for analogous compounds of NTE from IB - VIB group. Conclusions are presented. (author)

  2. Development of Detachable IORT Table for Colorectal Cancer

    International Nuclear Information System (INIS)

    Kim, Myung Se; Lee, Joon Ha

    1994-01-01

    In spite of remarkable improvement of surgical skills and anesthesia, local failure still occurred in 36-45% of locally advanced colorectal cancer after curative resection with or without pre-or post-operative irradiation. Intraoperative radiation therapy (IORT) is the ideal modality which respectable lesions are removed surgically and the remaining cancer nests are sterilized by irradiation during a surgical procedure. Therefore, the excellent local control without the damage of the adjacent normal tissues can be achieved. In IORT, judicious set up of the treatment cone on the treatment surface of the patient is required for accurate and homogenous dose distribution within treatment field, especially on the slopping surface of sacrum and pelvic sidewall which are the common sites of the local recurrence in rectal cancer. For this purpose, adequate coordination of gantry rotation and table tilting are essential. Adjusting gantry rotation is not difficult but tilting of the table is impossible inconventional treatment couch. Department of Therapeutic Radiology in Yeungnam University Medical Center developed the IORT table for colorectal cancer which is easy to set up and detach on head-down is about 30 degree which is efficient and easy-to-use, not only for IORT but also for colorectal surgery. So far, authors performed IORT with newly developed treatment table in 2 patients with rectal cancer and we found that this newly developed table could contribute in improving the dose distribution of IORT and surgical procedure for colorectal cancer

  3. NNDSS - Table I. infrequently reported notifiable diseases

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table I. infrequently reported notifiable diseases - 2017. In this Table, provisional cases of selected infrequently reported notifiable diseases (<1,000...

  4. NNDSS - Table I. infrequently reported notifiable diseases

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table I. infrequently reported notifiable diseases - 2014.In this Table, provisional cases of selected infrequently reported notifiable diseases (<1,000...

  5. NNDSS - Table I. infrequently reported notifiable diseases

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table I. infrequently reported notifiable diseases - 2015. In this Table, provisional cases of selected infrequently reported notifiable diseases (<1,000...

  6. NNDSS - Table I. infrequently reported notifiable diseases

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table I. infrequently reported notifiable diseases - 2018. In this Table, provisional cases of selected infrequently reported notifiable diseases (<1,000...

  7. Toddlers at the Table: Avoiding Power Struggles

    Science.gov (United States)

    ... Search English Español Toddlers at the Table: Avoiding Power Struggles KidsHealth / For Parents / Toddlers at the Table: ... common concerns into opportunities to teach healthy eating habits. Most Toddlers Are Picky Eaters Many toddlers express ...

  8. NNDSS - Table II. Babesiosis to Campylobacteriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Babesiosis to Campylobacteriosis - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  9. NNDSS - Table II. Cryptosporidiosis to Dengue

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Cryptosporidiosis to Dengue - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  10. NNDSS - Table II. Cryptosporidiosis to Dengue

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Cryptosporidiosis to Dengue - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the preceding...

  11. NNDSS - Table II. Shiga toxin to Shigellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Shiga toxin to Shigellosis - 2015. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  12. NNDSS - Table II. West Nile virus disease

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. West Nile virus disease - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year),...

  13. Handbook of thermodynamic tables and charts

    International Nuclear Information System (INIS)

    Raznjevic, K.

    1976-01-01

    A compilation of thermodynamic and thermophysical tables and charts is presented. Numerical values are cited in both technical and SI units. Solid, liquid, vapor, and gaseous forms of organic and inorganic materials are included. 12 figures, 137 tables

  14. Global Reference Tables for Management Information Systems

    Data.gov (United States)

    Social Security Administration — This database is a collection of reference tables that store common information used throughout SSA. These tables standardize code structures and code usage of SSA...

  15. NNDSS - Table II. Mumps to Rabies, animal

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Mumps to Rabies, animal - 2014.In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000 cases but...

  16. NNDSS - Table II. Mumps to Rabies, animal

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Mumps to Rabies, animal - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year),...

  17. NNDSS - Table II. Mumps to Rabies, animal

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Mumps to Rabies, animal - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the preceding...

  18. NNDSS - Table II. Legionellosis to Malaria

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Legionellosis to Malaria - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  19. NNDSS - Table II. Hepatitis (viral, acute) C

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Hepatitis (viral, acute) C - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  20. NNDSS - Table II. Babesiosis to Campylobacteriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Babesiosis to Campylobacteriosis - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  1. NNDSS - Table II. West Nile virus disease

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. West Nile virus disease - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year),...

  2. NNDSS - Table II. Giardiasis to Haemophilus influenza

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  3. NNDSS - Table II. Meningococcal to Pertussis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Meningococcal to Pertussis - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  4. NNDSS - Table II. Ehrlichiosis and Anaplasmosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Ehrlichiosis and Anaplasmosis - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  5. NNDSS - Table II. Cryptosporidiosis to Dengue

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Cryptosporidiosis to Dengue - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  6. NNDSS - Table II. Tetanus to Varicella

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Tetanus to Varicella - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year),...

  7. NNDSS - Table II. Chlamydia to Coccidioidomycosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Chlamydia to Coccidioidomycosis - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  8. NNDSS - Table II. Salmonellosis to Shigellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Salmonellosis to Shigellosis - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  9. NNDSS - Table II. West Nile to Zika

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. West Nile to Zika - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year), and...

  10. NNDSS - Table II. Babesiosis to Coccidioidomycosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Babesiosis to Coccidioidomycosis - 2014.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  11. Global Reference Tables for Production Systems

    Data.gov (United States)

    Social Security Administration — This database is a collection of reference tables that store common information used throughout SSA. These tables standardized code structures and code usage of SSA...

  12. NNDSS - Table II. Giardiasis to Haemophilus influenza

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2014. In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000...

  13. NNDSS - Table II. Giardiasis to Haemophilus influenza

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  14. NNDSS - Table II. Giardiasis to Haemophilus influenza

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  15. NNDSS - Table II. Giardiasis to Haemophilus influenza

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the...

  16. NNDSS - Table II. Hepatitis (viral, acute)

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Hepatitis (viral, acute) - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year),...

  17. NNDSS - Table II. Hepatitis (viral, acute)

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Hepatitis (viral, acute) - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the preceding...

  18. NNDSS - Table II. Hepatitis (viral, acute)

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Hepatitis (viral, acute) - 2014.In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000 cases but...

  19. NNDSS - Table II. Meningococcal disease to Pertussis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Meningococcal disease to Pertussis - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  20. NNDSS - Table II. Chlamydia to Coccidioidomycosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Chlamydia to Coccidioidomycosis - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the...

  1. NNDSS - Table II. Tetanus to Varicella

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Tetanus to Varicella - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year),...

  2. NNDSS - Table II. Invasive Pneumococcal to Legionellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Invasive Pneumococcal to Legionellosis - 2014.In this Table, all conditions with a 5-year average annual national total of more than or equals...

  3. Stream Tables and Watershed Geomorphology Education.

    Science.gov (United States)

    Lillquist, Karl D.; Kinner, Patricia W.

    2002-01-01

    Reviews copious stream tables and provides a watershed approach to stream table exercises. Results suggest that this approach to learning the concepts of fluvial geomorphology is effective. (Contains 39 references.) (DDR)

  4. NNDSS - Table II. Legionellosis to Malaria

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Legionellosis to Malaria - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  5. NNDSS - Table II. Lyme disease to Meningococcal

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Lyme disease to Meningococcal - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  6. NNDSS - Table II. Lyme disease to Meningococcal

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Lyme disease to Meningococcal - 2014In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000 cases...

  7. NNDSS - Table II. Lyme disease to Meningococcal

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Lyme disease to Meningococcal - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the...

  8. NNDSS - Table II. Salmonellosis to Shigellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Salmonellosis to Shigellosis - 2014.In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000 cases...

  9. NNDSS - Table II. West Nile virus disease

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. West Nile virus disease - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the preceding...

  10. NNDSS - Table II. Rubella to Salmonellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Rubella to Salmonellosis - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the preceding...

  11. NNDSS - Table II. Ehrlichiosis/Anaplasmosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Ehrlichiosis/Anaplasmosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  12. NNDSS - Table II. Tetanus to Vibriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Tetanus to Vibriosis - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the preceding year),...

  13. NNDSS - Table II. Shiga toxin to Shigellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Shiga toxin to Shigellosis - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the preceding...

  14. NNDSS - Table II. Babesiosis to Campylobacteriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Babesiosis to Campylobacteriosis - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the...

  15. NNDSS - Table II. Babesiosis to Campylobacteriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Babesiosis to Campylobacteriosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  16. NNDSS - Table II. Rubella to Salmonellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Rubella to Salmonellosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year),...

  17. NNDSS - Table II. Tetanus to Vibriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Tetanus to Vibriosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year), and...

  18. NNDSS - Table II. Chlamydia to Coccidioidomycosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Chlamydia to Coccidioidomycosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  19. NNDSS - Table II. Ehrlichiosis/Anaplasmosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Ehrlichiosis/Anaplasmosis - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the preceding...

  20. NNDSS - Table II. Invasive Pneumococcal to Legionellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Invasive Pneumococcal to Legionellosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  1. NNDSS - Table II. Invasive Pneumococcal to Legionellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Invasive Pneumococcal to Legionellosis - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the...

  2. Skeleton tables of burnout heat flux

    International Nuclear Information System (INIS)

    Kirillov, P.L.; Bobkov, V.P.; Boltenko, Eh.A.; Vinogradov, V.N.; Katan, I.B.; Smogalev, I.P.

    1991-01-01

    New methods of generating and arranging new reference data on critical thermal flux density during steam and water mixture flow in vertical round fubes are discussed. The modern requirements to such data include the assessment of data reliability and error, internal agreement, validation by physical and mathematical models, verification using a large amount of experimental results. The available reference data feature a number of drawbacks: they are not accurate enough and are limited by the parameters; other data feature a significant spread in values at the neighbouring values of parameters, discrepancy with the experimental results, not always substantiated extrapolations. A new version of skeleton tables, which are free from a major part of above disadvantages, is proposed

  3. On Importance of Rows for Decision Tables

    KAUST Repository

    AbouEisha, Hassan M.; Azad, Mohammad; Moshkov, Mikhail

    2017-01-01

    In this paper, we propose a method for the evaluation of importance of rows for decision tables. It is based on indirect information about changes in the set of reducts after removing the considered row from the table. We also discuss results of computer experiments with decision tables from UCI Machine Learning Repository.

  4. 21 CFR 890.3750 - Mechanical table.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mechanical table. 890.3750 Section 890.3750 Food... DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3750 Mechanical table. (a) Identification. A mechanical table is a device intended for medical purposes that has a flat surface that can be...

  5. On Importance of Rows for Decision Tables

    KAUST Repository

    AbouEisha, Hassan M.

    2017-06-21

    In this paper, we propose a method for the evaluation of importance of rows for decision tables. It is based on indirect information about changes in the set of reducts after removing the considered row from the table. We also discuss results of computer experiments with decision tables from UCI Machine Learning Repository.

  6. The Different Periodic Tables of Dmitrii Mendeleev

    Science.gov (United States)

    Laing, Michael

    2008-01-01

    Between 1869 and 1905 the Russian chemist Dmitrii Mendeleev published several tables with different arrangements of the chemical elements. Four of these are compared with periodic tables by Russian scientists from 1934 and 1969. The difficulties caused by the lanthanoid elements are clearly seen in the table of 1905, which satisfactorily includes…

  7. Cohort Working Life Tables for Older Canadians

    Directory of Open Access Journals (Sweden)

    Frank T. Denton

    2010-12-01

    those based on the period tables, for both men and women, and that is reflected in increased retirement expectancies. For example, a male aged 50 in 1976 could have expected to live three years longer and to have almost four more years in retirement, based on the male cohort table under medium assumptions, as compared with the corresponding period table.

  8. Hydrography - MO 2014 Class L1 Lake Watersheds WQS TableG (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — This feature class contains watersheds for Class L1 lakes listed in Table G - Lake Classifications and Use Designations of the Water Quality Standards rule published...

  9. Guide to mathematical tables supplement no 1

    CERN Document Server

    Burunova, N M; Fedorova, R M

    1960-01-01

    A Guide to Mathematical Tables is a supplement to the Guide to Mathematical Tables published by the U.S.S.R. Academy of Sciences in 1956. The tables contain information on subjects such as powers, rational and algebraic functions, and trigonometric functions, as well as logarithms and polynomials and Legendre functions. An index listing all functions included in both the Guide and the Supplement is included.Comprised of 15 chapters, this supplement first describes mathematical tables in the following order: the accuracy of the table (that is, the number of decimal places or significant

  10. Measuring scarce water saving from interregional virtual water flows in China

    Science.gov (United States)

    Zhao, X.; Li, Y. P.; Yang, H.; Liu, W. F.; Tillotson, M. R.; Guan, D.; Yi, Y.; Wang, H.

    2018-05-01

    Trade of commodities can lead to virtual water flows between trading partners. When commodities flow from regions of high water productivity to regions of low water productivity, the trade has the potential to generate water saving. However, this accounting of water saving does not account for the water scarcity status in different regions. It could be that the water saving generated from this trade occurs at the expense of the intensified water scarcity in the exporting region, and exerts limited effect on water stress alleviation in importing regions. In this paper, we propose an approach to measure the scarce water saving associated with virtual water trade (measuring in water withdrawal/use). The scarce water is quantified by multiplying the water use in production with the water stress index (WSI). We assessed the scarce water saving/loss through interprovincial trade within China using a multi-region input-output table from 2010. The results show that interprovincial trade resulted in 14.2 km3 of water loss without considering water stress, but only 0.4 km3 scarce water loss using the scarce water concept. Among the 435 total connections of virtual water flows, 254 connections contributed to 20.2 km3 of scarce water saving. Most of these connections are virtual water flows from provinces with lower WSI to that with higher WSI. Conversely, 175 connections contributed to 20.6 km3 of scarce water loss. The virtual water flow connections between Xinjiang and other provinces stood out as the biggest contributors, accounting for 66% of total scarce water loss. The results show the importance of assessing water savings generated from trade with consideration of both water scarcity status and water productivity across regions. Identifying key connections of scarce water saving is useful in guiding interregional economic restructuring towards water stress alleviation, a major goal of China’s sustainable development strategy.

  11. Table-top job analysis

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-01

    The purpose of this Handbook is to establish general training program guidelines for training personnel in developing training for operation, maintenance, and technical support personnel at Department of Energy (DOE) nuclear facilities. TTJA is not the only method of job analysis; however, when conducted properly TTJA can be cost effective, efficient, and self-validating, and represents an effective method of defining job requirements. The table-top job analysis is suggested in the DOE Training Accreditation Program manuals as an acceptable alternative to traditional methods of analyzing job requirements. DOE 5480-20A strongly endorses and recommends it as the preferred method for analyzing jobs for positions addressed by the Order.

  12. Trench water chemistry at commercially operated low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    Pietrzak, R.F.; Dayal, R.; Kinsley, M.T.; Clinton, J.; Czyscinski, K.S.; Weiss, A.J.

    1982-01-01

    Water samples from the disposal trenches of two low-level radioactive-waste-disposal sites were analyzed for their inorganic, organic, and radionuclide contents. Since oxidation of the trench waters can occur during their movement along the groundwater flow path, experiments were performed to measure the chemical and physical changes that occur in these waters upon oxidation. Low concentrations of chelating agents, shown to exist in trench waters, may be responsible for keeping radionuclides, particularly 60 Co, in solution. 4 figures, 5 tables

  13. Water

    Science.gov (United States)

    ... drink and water in food (like fruits and vegetables). 6. Of all the earth’s water, how much is ocean or seas? 97 percent of the earth’s water is ocean or seas. 7. How much of the world’s water is frozen? Of all the water on earth, about 2 percent is frozen. 8. How much ...

  14. A table-top LHC

    CERN Multimedia

    Barbara Warmbein

    2011-01-01

    Many years ago, when ATLAS was no more than a huge empty underground cavern and Russian artillery shell casings were being melted down to become part of the CMS calorimetry system, science photographer Peter Ginter started documenting the LHC’s progress. He was there when special convoys of equipment crossed the Jura at night, when cranes were lowering down detector slices and magnet coils were being wound in workshops. Some 18 years of LHC history have been documented by Ginter, and the result has just come out as a massive coffee table book full of double-page spreads of Ginter’s impressive images.   The new coffee table book, LHC: the Large Hadron Collider. Published by the Austrian publisher Edition Lammerhuber in cooperation with CERN and UNESCO Publishing, LHC: the Large Hadron Collider is an unusual piece in the company’s portfolio. As the publisher’s first science book, LHC: the Large Hadron Collider weighs close to five kilos and comes in a s...

  15. Efeito do manejo do lençol freático na adaptação fisiomorfológica de duas espécies de trigo ao encharcamento Effect of the water table management in the morpho-physiological adaptation of two wheat species to waterlogging

    Directory of Open Access Journals (Sweden)

    Rinaldo de O. Calheiros

    2000-01-01

    Full Text Available Estudou-se o efeito de três manejos do lençol freático na indução de adaptações fisiomorfológicas dos trigos Triticum aestivum L. e Triticum durum L. à hipoxia, caracterizando e inferindo a influência relativa dos principais fatores físicos e biológicos interferentes. O experimento foi conduzido na ESALQ/USP, Piracicaba, SP, simulando-se ao máximo um meio físico/condição natural de uma várzea. Após a indução na fase vegetativa, através de períodos hipóxicos com duração progressiva, o grau de adaptação foi avaliado através de inundação permanente, incluindo o florescimento/formação de grãos. Observou-se: resposta diferenciada de exigência e/ou capacidade de extração de nutrientes entre as duas espécies; que a adubação foliar foi ineficiente para suprir as deficiências nutricionais da planta; que os manejos com curtos períodos de hipoxia induziram o trigo a adaptações fisiomorfológicas, porém não na intensidade ou eficiência de que resultassem parâmetros de produção em níveis adequados; enfim, que o manejo com o lençol freático mantido a 15 cm de profundidade durante todo o ciclo cultural foi o que propiciou melhor desempenho do trigo em cultivo sob encharcamento.The effect of three different water table managements in the morpho-physiological adaptation to waterlogging of Triticum aestivum, L. and Triticum durum, L., and the relative influence of the main physical and biological interferance factors were studied. The trial was conducted at ESALQ/USP, Piracicaba, SP, under simulated conditions of a natural low land. After introduction of stress adaptation during the vegetative growth stage, while applying progressive times of hipoxics periods, there were observed different requirements and/or extraction capacities of nutrients between the two species; the fertilization on leaves was not enough to avoid nutritional deficiencies in wheat under hipoxia. The water table management used resulted in

  16. Introduction to naturally occurring radioactive material

    International Nuclear Information System (INIS)

    Egidi, P.

    1997-01-01

    Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. Some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose-based standards. So when is TENORM a problem? Where is it a problem? That depends on when, where, and whom you talk to exclamation point We will start by reviewing background radioactivity, then we will proceed to the geology, mobility, and variability of these

  17. Introduction to naturally occurring radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Egidi, P.

    1997-08-01

    Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. We are also bathed in a sea of natural radiation coming from the sun and deep space. Living systems have adapted to these levels of radiation and radioactivity. But some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Other activities, such as flying at high altitudes, expose us to elevated levels of NORM. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose

  18. Geochemical evolution of acidic ground water at a reclaimed surface coal mine in western Pennsylvania

    Science.gov (United States)

    Cravotta,, Charles A.

    1991-01-01

    Concentrations of dissolved sulfate and acidity in ground water increase downflow in mine spoil and underlying bedrock at a reclaimed surface coal mine in the bituminous field of western Pennsylvania. Elevated dissolved sulfate and negligible oxygen in ground water from bedrock about 100 feet below the water table suggest that pyritic sulfur is oxidized below the water table, in a system closed to oxygen. Geochemical models for the oxidation of pyrite (FeS2) and production of sulfate (SO42-) and acid (H+) are presented to explain the potential role of oxygen (O2) and ferric iron (Fe3+) as oxidants. Oxidation of pyrite by O2 and Fe3+ can occur under oxic conditions above the water table, whereas oxidation by Fe3+ also can occur under anoxic conditions below the water table. The hydrated ferric-sulfate minerals roemerite [Fe2+Fe43+(SO4)4·14H2O], copiapite [Fe2+Fe43+(SO4)6(OH)2·20H20], and coquimbite [Fe2(SO4)3·9H2O] were identified with FeS2 in coal samples, and form on the oxidizing surface of pyrite in an oxic system above the water table. These soluble ferric-sulfate 11 salts11 can dissolve with recharge waters or a rising water table releasing Fe3+, SO42-. and H+, which can be transported along closed-system ground-water flow paths to pyrite reaction sites where O2 may be absent. The Fe3+ transported to these sites can oxidize pyritic sulfur. The computer programs WATEQ4F and NEWBAL were used to compute chemical speciation and mass transfer, respectively, considering mineral dissolution and precipitation reactions plus mixing of waters from different upflow zones. Alternative mass-balance models indicate that (a) extremely large quantities of O2, over 100 times its aqueous solubility, can generate the observed concentrations of dissolved SO42- from FeS2, or (b) under anoxic conditions, Fe3+ from dissolved ferric-sulfate minerals can oxidize FeS2 along closed-system ground-water flow paths. In a system open to O2, such as in the unsaturated zone, the aqueous

  19. Water

    Science.gov (United States)

    ... can be found in some metal water taps, interior water pipes, or pipes connecting a house to ... reduce or eliminate lead. See resources below. 5. Children and pregnant women are especially vulnerable to the ...

  20. Health effects assessment summary tables

    International Nuclear Information System (INIS)

    1999-01-01

    The document is an excellent pointer system to identify current literature or changes in assessment criteria for many chemicals of interest to Superfund. It was prepared for Superfund use by the Environmental Criteria and Assessment Office (ECAO-Cin) in EPA's Office of Health and Environmental Assessment. Chemicals considered are those for which Health Effects Assessment Documents, Health and Environmental Effects Profiles, Health Assessment Documents or Air Quality Criteria Documents have been prepared by ECAO. Radionuclides considered are those believed to be most common at Superfund sites. Tables summarize reference doses (RfDs) for toxicity from subchronic and chronic inhalation, oral exposure, slope factors and unit risk values for carcinogenicity based on lifetime inhalation and oral exposure, and radionuclide carcinogenicity

  1. Setting Places at the Table

    Directory of Open Access Journals (Sweden)

    James R. Briscoe

    2016-12-01

    Full Text Available A recent survey by the National Endowment for the Arts found that only 2% of Americans listen to “Classical” music with regularity, and fewer practice or play art or historic music even once in a year. The rotating kaleidoscope of new technologies, repertories, interpretation, and cultural values can become not an ultimate bewilderment, a nail in the coffin of art and historic music, but a powerful tool for revitalizing how it engages persons of all age groups and how it can broaden its understanding. The table of musical places we set can respond to the narrative we carefully conceive for any condition at hand, for the student or scholar or layperson we address, for an intentional kaleidoscope of presentations. Such an attitude might let the other 98% discover art and historic music and see their lives mirrored and bettered.

  2. The periodic table in Flatland

    International Nuclear Information System (INIS)

    Kibler, M.

    1995-01-01

    The D-dimensional Coulomb system serves as a starting point for generating generalized atomic shells. These shells are ordered according to a generalized Madelung rule in D dimensions. This rule together with an Aufbau Prinzip is applied to produce a D-dimensional periodic table. A model is developed to rationalize the ordering of the shells predicted by the generalized Madelung rule. This model is based on the introduction of an Hamiltonian, invariant under the q-deformed algebra U q (so(D)), that breaks down the SO (D + 1) dynamical symmetry of the hydrogen atom in D dimensions. The D = 2 case (Flatland) is investigated with some details. It is shown that the neutral atoms and the (moderately) positive ions correspond to the values q = 0.8 and q = 1, respectively, of the deformation parameter q. (authors). 55 refs

  3. An ECR table plasma generator

    International Nuclear Information System (INIS)

    Racz, R.; Palinkas, J.; Bin, S.

    2012-01-01

    A compact ECR plasma device was built in our lab using the 'spare parts' of the ATOMKI ECR ion source. We call it 'ECR Table Plasma Generator'. It consists of a relatively big plasma chamber (ID=10 cm, L=40 cm) in a thin NdFeB hexapole magnet with independent vacuum and gas dosing systems. For microwave coupling two low power TWTAs (Travelling Wave tube amplifier) can be applied individually or simultaneously, operating in the 6-18 GHz range. There is no axial magnetic trap and there is no extraction. The technical details of the plasma generator and preliminary plasma photo study results are shown. This paper is followed by the associated poster. (authors)

  4. A periodic table for cancer.

    Science.gov (United States)

    Epstein, Richard J

    2015-01-01

    Cancers exhibit differences in metastatic behavior and drug sensitivity that correlate with certain tumor-specific variables such as differentiation grade, growth rate/extent and molecular regulatory aberrations. In practice, patient management is based on the past results of clinical trials adjusted for these biomarkers. Here, it is proposed that treatment strategies could be fine-tuned upfront simply by quantifying tumorigenic spatial (cell growth) and temporal (genetic stability) control losses, as predicted by genetic defects of cell-cycle-regulatory gatekeeper and genome-stabilizing caretaker tumor suppressor genes, respectively. These differential quantifications of tumor dysfunction may in turn be used to create a tumor-specific 'periodic table' that guides rational formulation of survival-enhancing anticancer treatment strategies.

  5. Environmental regulatory update table, March 1989

    International Nuclear Information System (INIS)

    Houlberg, L.; Langston, M.E.; Nikbakht, A.; Salk, M.S.

    1989-04-01

    The Environmental Regulatory Update Table provides information on regulatory initiatives of interest to DOE operations and contractor staff with environmental management responsibilities. The table is updated each month with information from the Federal Register and other sources, including direct contact with regulatory agencies. Each table entry provides a chronological record of the rulemaking process for that initiative with an abstract and a projection of further action

  6. Environmental Regulatory Update Table, April 1989

    International Nuclear Information System (INIS)

    Houlberg, L.; Langston, M.E.; Nikbakht, A.; Salk, M.S.

    1989-05-01

    The Environmental Regulatory Update Table provides information on regulatory initiatives of interest to DOE operations and contractor staff with environmental management responsibilities. The table is updated each month with information from the Federal Register and other sources, including direct contact with regulatory agencies. Each table entry provides a chronological record of the rulemaking process for that initiative with an abstract and a projection of further action

  7. Environmental Regulatory Update Table, August 1991

    Energy Technology Data Exchange (ETDEWEB)

    Houlberg, L.M., Hawkins, G.T.; Salk, M.S.

    1991-09-01

    This Environmental Regulatory Update Table (August 1991) provides information on regulatory initiatives of interest to DOE operations and contractor staff with environmental management responsibilities. The table is updated each month with information from the Federal Register and other sources, including direct contact with regulatory agencies. Each table entry provides a chronological record of the rulemaking process for that initiative with an abstract and a projection of further action.

  8. Environmental Regulatory Update Table, December 1989

    International Nuclear Information System (INIS)

    Houlbert, L.M.; Langston, M.E.; Nikbakht, A.; Salk, M.S.

    1990-01-01

    The Environmental Regulatory Update Table provides information on regulatory initiatives of interest to DOE operations and contractor staff with environmental management responsibilities. The table is updated each month with information from the Federal Register and other sources, including direct contact with regulatory agencies. Each table entry provides a chronological record of the rulemaking process for that initiative with an abstract and a projection of further action

  9. Thermodynamic tables to accompany Modern engineering thermodynamics

    CERN Document Server

    Balmer, Robert T

    2011-01-01

    This booklet is provided at no extra charge with new copies of Balmer's Modern Engineering Thermodynamics. It contains two appendices. Appendix C contains 40 thermodynamic tables, and Appendix D consists of 6 thermodynamic charts. These charts and tables are provided in a separate booklet to give instructors the flexibility of allowing students to bring the tables into exams. The booklet may be purchased separately if needed.

  10. Environmental Regulatory Update Table, December 1991

    Energy Technology Data Exchange (ETDEWEB)

    Houlberg, L.M.; Hawkins, G.T.; Salk, M.S.

    1992-01-01

    The Environmental Regulatory Update Table provides information on regulatory initiatives of interest to DOE operations and contractor staff with environmental management responsibilities. The table is updated each month with information from the Federal Register and other sources, including direct contact with regulatory agencies. Each table entry provides a chronological record of the rulemaking process for that initiative with an abstract and a projection of further action.

  11. A table top exercise and workshop

    International Nuclear Information System (INIS)

    Lakey, J.R.A.

    1992-01-01

    Table top exercises are widely applied in training for emergency preparedness and have long been a feature of Courses on Planning for Nuclear Emergencies. Experience of a large number of table top exercises is used to provide a classification of the types of exercise indicating the application and the disadvantages. The use of workshops is considered to be complementary rather than an alternative to teaching methods available from table top exercises. (author)

  12. Environmental Regulatory Update Table, August 1990

    International Nuclear Information System (INIS)

    Houlberg, L.M.; Nikbakht, A.; Salk, M.S.

    1990-09-01

    The Environmental Regulatory Update Table provides information on regulatory initiatives of interest to DOE operations and contractor staff with environmental management responsibilities. The table is updated each month with information from the Federal Register and other sources, including direct contact with regulatory agencies. Each table entry provides a chronological record of the rulemaking process for that initiative with an abstract and a projection of further action

  13. Environmental Regulatory Update Table, October 1991

    Energy Technology Data Exchange (ETDEWEB)

    Houlberg, L.M.; Hawkins, G.T.; Salk, M.S.

    1991-11-01

    The Environmental Regulatory Update Table provides information on regulatory initiatives of interest to DOE operations and contractor staff with environmental management responsibilities. The table is updated each month with information from the Federal Register and other sources, including direct contact with regulatory agencies. Each table entry provides a chronological record of the rulemaking process for that initiative with an abstract and a projection of further action.

  14. Environmental Regulatory Update Table, November 1991

    Energy Technology Data Exchange (ETDEWEB)

    Houlberg, L.M.; Hawkins, G.T.; Salk, M.S.

    1991-12-01

    The Environmental Regulatory Update Table provides information on regulatory initiatives of interest to DOE operations and contractor staff with environmental management responsibilities. The table is updated each month with information from the Federal Register and other sources, including direct contact with regulatory agencies. Each table entry provides a chronological record of the rulemaking process for that initiative with an abstract and a projection of further action.

  15. Environmental Regulatory Update Table, September 1991

    Energy Technology Data Exchange (ETDEWEB)

    Houlberg, L.M.; Hawkins, G.T.; Salk, M.S.

    1991-10-01

    The Environmental Regulatory Update Table provides information on regulatory initiatives of interest to DOE operations and contractor staff with environmental management responsibilities. The table is updated each month with information from the Federal Register and other sources, including direct contact with regulatory agencies. Each table entry provides a chronological record of the rulemaking process for that initiative with an abstract and a projection of further action.

  16. Environmental regulatory update table, July 1991

    Energy Technology Data Exchange (ETDEWEB)

    Houlberg, L.M.; Hawkins, G.T.; Salk, M.S.

    1991-08-01

    This Environmental Regulatory Update Table (July 1991) provides information on regulatory initiatives of interest to DOE operations and contractor staff with environmental management responsibilities. The table is updated each month with information from the Federal Register and other sources, including direct contact with regulatory agencies. Each table entry provides a chronological record of the rulemaking process for that initiative with an abstract and a projection of further action.

  17. Relative leach behavior of waste glasses and naturally occurring glasses

    International Nuclear Information System (INIS)

    Adams, P.B.

    1979-01-01

    Simulated nuclear waste glasses of the sodium-borosilicate type with a low waste loading and of the zinc-borosilicate type with a high waste loading have been compared with obsidians. The resuls indicate that the waste glasses would corrode in normal natural environments at a rate of about 0.1 μm per year at 30 0 C and about 5 μm per year at 90 0 C, compared with obsidians which seem to corrode at, or less than, about 0.01 μm per year at 30 0 C and less than 1 μm per year at 90 0 C. Activation energies for reactions of the two waste glasses with pure water are about 20 kcal/g-mol. 3 figures, 7 tables

  18. Table of specific activities of selected isotopes

    International Nuclear Information System (INIS)

    Shipley, G.

    The bulk of this publication consists of a table of the half-lives, decay modes, and specific activities of isotopes selected for their particular interest to the Environmental Health and Safety Department, LBL. The specific activities were calculated with a PDP 9/15 computer. Also included in the report is a table of stable isotopes, the Th and U decay chains, a chart of the nuclides for elements 101 through 106, the heavy element region of the periodic table, and a specific activity monograph. 5 figures, 2 tables

  19. Brief description as of April, 1968, of the geology and hydrology of the Lake Minnequa area, Pueblo, Colorado, and suggested solutions for trouble caused by a high water table

    Science.gov (United States)

    Scott, Glenn R.

    1972-01-01

    Lake Minnequa lies in a poorly drained broad upland buried valley west of the valley of Salt Creek. Immediately north of Lake Minnequa the buried valley is sharply constricted in sees. 11 and 12, T. 21 S., R. 65 W., where it is entrenched in a buried ridge of bedrock (see geologic map).  The bedrock throughout the buried valley is composed of calcareous shale, limestone, and chalk of the Smoky Hill Shale Member of the Niobrara Formation.  These beds are relatively impermeable to the flow of ground water, but contribute large quantities of sodium sulfate to both the surface and ground water.

  20. Scenario-based table top simulations

    DEFF Research Database (Denmark)

    Broberg, Ole; Edwards, Kasper; Nielsen, J.

    2012-01-01

    This study developed and tested a scenario-based table top simulation method in a user-driven innovation setting. A team of researchers worked together with a user group of five medical staff members from the existing clinic. Table top simulations of a new clinic were carried out in a simple model...